30 (thirty) is the
natural number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country").
Numbers used for counting are called ''Cardinal n ...
following
29 and preceding
31.
In mathematics
![Square pyramidal number](https://upload.wikimedia.org/wikipedia/commons/4/47/Square_pyramidal_number.svg)
30 is an
even
Even may refer to:
General
* Even (given name), a Norwegian male personal name
* Even (surname)
* Even (people), an ethnic group from Siberia and Russian Far East
** Even language, a language spoken by the Evens
* Odd and Even, a solitaire game w ...
,
composite
Composite or compositing may refer to:
Materials
* Composite material, a material that is made from several different substances
** Metal matrix composite, composed of metal and other parts
** Cermet, a composite of ceramic and metallic materials
...
,
pronic number. With
2,
3, and
5 as its
prime factor
A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...
s, it is a
regular number and the first
sphenic number, the smallest of the form , where is a prime greater than 3. It has an
aliquot sum of
42, which is the second sphenic number.
It is also:
* A
semiperfect number
In number theory, a semiperfect number or pseudoperfect number is a natural number ''n'' that is equal to the sum of all or some of its proper divisors. A semiperfect number that is equal to the sum of all its proper divisors is a perfect number.
...
, since adding some subsets of its divisors (e.g., 5, 10 and 15) equals 30.
* A
primorial
In mathematics, and more particularly in number theory, primorial, denoted by "#", is a function from natural numbers to natural numbers similar to the factorial function, but rather than successively multiplying positive integers, the function ...
.
* A
Harshad number
In mathematics, a harshad number (or Niven number) in a given number base is an integer that is divisible by the sum of its digits when written in that base.
Harshad numbers in base are also known as -harshad (or -Niven) numbers.
Harshad numbers ...
in
decimal
The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...
.
* Divisible by the number of
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...
s (
10) below it.
* The largest number such that all
coprimes smaller than itself, except for 1, are prime.
* The sum of the first four squares, making it a
square pyramidal number
In mathematics, a pyramid number, or square pyramidal number, is a natural number that counts the number of stacked spheres in a pyramid with a square base. The study of these numbers goes back to Archimedes and Fibonacci. They are part of a broa ...
.
* The number of
vertices in the
Tutte–Coxeter graph.
* The measure of the
central angle
A central angle is an angle whose apex (vertex) is the center O of a circle and whose legs (sides) are radii intersecting the circle in two distinct points A and B. Central angles are subtended by an arc between those two points, and the arc le ...
and
exterior angle
In geometry, an angle of a polygon is formed by two sides of the polygon that share an endpoint. For a simple (non-self-intersecting) polygon, regardless of whether it is convex or non-convex, this angle is called an interior angle (or ) if ...
of a
dodecagon
In geometry, a dodecagon or 12-gon is any twelve-sided polygon.
Regular dodecagon
A regular dodecagon is a figure with sides of the same length and internal angles of the same size. It has twelve lines of reflective symmetry and rotational sym ...
, which is the
petrie polygon of the
24-cell
In geometry, the 24-cell is the convex regular 4-polytope (four-dimensional analogue of a Platonic solid) with Schläfli symbol . It is also called C24, or the icositetrachoron, octaplex (short for "octahedral complex"), icosatetrahedroid, oct ...
.
* The number of
sides of a
triacontagon
In geometry, a triacontagon or 30-gon is a thirty-sided polygon. The sum of any triacontagon's interior angles is 5040 degrees.
Regular triacontagon
The '' regular triacontagon'' is a constructible polygon, by an edge- bisection of a regular ...
, which in turn is the petrie polygon of the
120-cell
In geometry, the 120-cell is the convex regular 4-polytope (four-dimensional analogue of a Platonic solid) with Schläfli symbol . It is also called a C120, dodecaplex (short for "dodecahedral complex"), hyperdodecahedron, polydodecahedron, heca ...
and
600-cell.
* The number of sides of a
dodecahedron and
icosahedron
In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes and . The plural can be either "icosahedra" () or "icosahedrons".
There are infinitely many non- similar shapes of icosahedra, some of them being more symmetrica ...
, of vertices of an
icosidodecahedron, and of
faces of a
rhombic dodecahedron.
* The sum of the number of
elements
Element or elements may refer to:
Science
* Chemical element, a pure substance of one type of atom
* Heating element, a device that generates heat by electrical resistance
* Orbital elements, parameters required to identify a specific orbit of ...
of a
5-cell
In geometry, the 5-cell is the convex 4-polytope with Schläfli symbol . It is a 5-vertex four-dimensional object bounded by five tetrahedral cells. It is also known as a C5, pentachoron, pentatope, pentahedroid, or tetrahedral pyramid. It i ...
: 5 vertices, 10
edges
Edge or EDGE may refer to:
Technology Computing
* Edge computing, a network load-balancing system
* Edge device, an entry point to a computer network
* Adobe Edge, a graphical development application
* Microsoft Edge, a web browser developed by ...
, 10
faces, and 5
cells
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
.
* The
Coxeter number
In mathematics, the Coxeter number ''h'' is the order of a Coxeter element of an irreducible Coxeter group. It is named after H.S.M. Coxeter.
Definitions
Note that this article assumes a finite Coxeter group. For infinite Coxeter groups, there a ...
of
''E''8.
Furthermore,
In a
group , such that
, where does not divide , and has a subgroup of order
, 30 is the only number less than 60 that is neither a prime nor of the aforementioned form. Therefore, 30 is the only candidate for the order of a
simple group less than 60, in which one needs other methods to specifically reject to eventually deduce said order.
In science
* The
atomic number
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every ...
of
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
is 30.
Astronomy
*
Messier object M30, a
magnitude 8.5
globular cluster in the
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
Capricornus
* The
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and ...
object
NGC 30
NGC commonly refers to:
* New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy
NGC may also refer to:
Companies
* NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998
* Nati ...
, a double star in the constellation
Pegasus
Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as hor ...
Age 30
* The minimum age for United States senators.
* In some regions of the continental United States, the 30th birthday is celebrated by gifting sticks.
In other fields
Thirty is:
* Used (as
–30–
-30- has been traditionally used by journalists in North America to indicate the end of a story or article that is submitted for editing and typesetting. It is commonly employed when writing on deadline and sending bits of the story at a time, v ...
) to indicate the end of a newspaper (or broadcast) story, a copy editor's typographical notation
* The number of days in the months April, June, September and November (and in unusual circumstances February—see
February 30
Several non-standard dates are used in calendars. Some are used sarcastically, some for scientific or mathematical purposes, and some for exceptional or fictional calendars.
January 0
January 0 or 0 January is an alternative name for December 31 ...
)
* The total number of major and minor keys in Western
tonal music
Tonality is the arrangement of pitches and/or chords of a musical work in a hierarchy of perceived relations, stabilities, attractions and directionality. In this hierarchy, the single pitch or triadic chord with the greatest stability is call ...
, including enharmonic equivalents
* In years of marriage, the pearl
wedding anniversary
A wedding anniversary is the anniversary of the date a wedding took place. Couples may take the occasion to celebrate their relationship, either privately or with a larger party. Special celebrations and gifts are often given for particular an ...
* The duration in years of the
Thirty Years' War
The Thirty Years' War was one of the longest and most destructive conflicts in European history
The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (80 ...
- 1618 to 1648
* The
code for international direct dial phone calls to
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
* The house number of
30 St Mary Axe
30 St Mary Axe (previously known as the Swiss Re Building and informally known as the Gherkin) is a commercial skyscraper in London's primary financial district, the City of London. It was completed in December 2003 and opened in April 2004. W ...
(The Gherkin)
* The number of tracks on
The Beatles
The Beatles were an English Rock music, rock band, formed in Liverpool in 1960, that comprised John Lennon, Paul McCartney, George Harrison and Ringo Starr. They are regarded as the Cultural impact of the Beatles, most influential band of al ...
' eponymous
album
An album is a collection of audio recordings issued on compact disc (CD), Phonograph record, vinyl, audio tape, or another medium such as Digital distribution#Music, digital distribution. Albums of recorded sound were developed in the early ...
, usually known as ''
The White Album
''The Beatles'', also referred to colloquially as the White Album, is the ninth studio album and only double album by the English rock band the Beatles, released on 22 November 1968. Featuring a plain white sleeve, the cover contains no graph ...
''
* A stage in
young adulthood
A young adult is generally a person in the years following adolescence. Definitions and opinions on what qualifies as a young adult vary, with works such as Erik Erikson's stages of human development significantly influencing the definition of ...
* Part of the name of:
**
30 Odd Foot of Grunts
30 Odd Foot of Grunts were an Australian rock group, formed in 1992, with Russell Crowe
Russell Ira Crowe (born 7 April 1964) is an actor. He was born in New Zealand, spent ten years of his childhood in Australia, and moved there permane ...
, the band fronted by actor Russell Crowe
** The movie title ''
13 Going on 30
''13 Going on 30'' (released as ''Suddenly 30'' in some countries) is a 2004 American fantasy romantic comedy film written by Cathy Yuspa and Josh Goldsmith, directed by Gary Winick, and starring Jennifer Garner. It follows a 13-year-old girl in ...
'', starring
Jennifer Garner
** The title of the
Food Network show
Show or The Show may refer to:
Competition, event, or artistic production
* Agricultural show, associated with agriculture and animal husbandry
* Animal show, a judged event in the hobby of animal fancy
** Cat show
** Dog show
** Horse show
** Sp ...
''
30 Minute Meals
''30 Minute Meals'' is a Food Network show hosted by Rachael Ray. Her first of four shows on Food Network, its original run aired from November 17, 2001, until May 5, 2012. The show specializes in convenience cooking for those with little time ...
''
** ''
30 Days of Night
''30 Days of Night'' is a three-issue horror comic book miniseries written by Steve Niles, illustrated by Ben Templesmith, and published by American company IDW Publishing in 2002. All three parties co-own the property.
The series takes place i ...
'', a comic book miniseries and
film
A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...
*
Judas Iscariot
Judas Iscariot (; grc-x-biblical, Ἰούδας Ἰσκαριώτης; syc, ܝܗܘܕܐ ܣܟܪܝܘܛܐ; died AD) was a disciple and one of the original Twelve Apostles of Jesus Christ. According to all four canonical gospels, Judas betraye ...
betrayed
Jesus
Jesus, likely from he, יֵשׁוּעַ, translit=Yēšūaʿ, label=Hebrew/Aramaic ( AD 30 or 33), also referred to as Jesus Christ or Jesus of Nazareth (among other names and titles), was a first-century Jewish preacher and religious ...
for
30 pieces of silver
Thirty pieces of silver was the price for which Judas Iscariot betrayed Jesus, according to an account in the Gospel of Matthew 26:15 in the New Testament. Before the Last Supper, Judas is said to have gone to the chief priests and agreed to hand ...
(
Matthew
Matthew may refer to:
* Matthew (given name)
* Matthew (surname)
* ''Matthew'' (ship), the replica of the ship sailed by John Cabot in 1497
* ''Matthew'' (album), a 2000 album by rapper Kool Keith
* Matthew (elm cultivar), a cultivar of the Ch ...
26:15)
* The number of the French department
Gard
Gard () is a department in Southern France, located in the region of Occitanie. It had a population of 748,437 as of 2019;[Bulgarian alphabet
The Bulgarian Cyrillic alphabet is used to write the Bulgarian language.
The Cyrillic alphabet was originally developed in the First Bulgarian Empire during the 9th – 10th century AD at the Preslav Literary School.
It has been used in Bulgaria ...]
* Number of letters in
Serbian alphabet
The Serbian Cyrillic alphabet ( sr, / , ) is a variation of the Cyrillic script used to write the Serbian language, updated in 1818 by Serbian linguist Vuk Karadžić. It is one of the two alphabets used to write standard modern Serbian, th ...
* 30 was the route number of the bus blown up by terrorists in
Tavistock Square during the
7 July 2005 London bombings
The 7 July 2005 London bombings, often referred to as 7/7, were a series of four coordinated suicide attacks carried out by Islamic terrorists in London that targeted commuters travelling on the city's public transport system during the mo ...
.
History and literature
* At about age 30 (according to Luke 3:23),
Jesus
Jesus, likely from he, יֵשׁוּעַ, translit=Yēšūaʿ, label=Hebrew/Aramaic ( AD 30 or 33), also referred to as Jesus Christ or Jesus of Nazareth (among other names and titles), was a first-century Jewish preacher and religious ...
of Nazareth was baptized by
John the Baptist
John the Baptist or , , or , ;Wetterau, Bruce. ''World history''. New York: Henry Holt and Company. 1994. syc, ܝܘܿܚܲܢܵܢ ܡܲܥܡܕ݂ܵܢܵܐ, Yoḥanān Maʿmḏānā; he, יוחנן המטביל, Yohanān HaMatbil; la, Ioannes Bapti ...
, signaling the beginning of his public ministry of teaching and healing. It was also the age when
David
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". w ...
became King (2 Samuel 5:4) and
Ezekiel
Ezekiel (; he, יְחֶזְקֵאל ''Yəḥezqēʾl'' ; in the Septuagint written in grc-koi, Ἰεζεκιήλ ) is the central protagonist of the Book of Ezekiel in the Hebrew Bible.
In Judaism, Christianity, and Islam, Ezekiel is acknow ...
and John the Baptist began their own ministries, (based on Ezekiel 1:1 and John the Baptist's age in comparison to Jesus.)
* Age 30 is when Jewish priests traditionally start their service (according to Numbers 4:3).
* One of the rallying-cries of the 1960s student/youth protest movement was the slogan, '
Don't trust anyone over thirty
Don't, Dont, or DONT may refer to:
Films
* ''Don't'' (1925 film), a 1925 silent comedy film
* ''Don't'' (1974 film), a 1974 film about the monarch butterfly
* ''Don't'', a fake trailer from the film ''Grindhouse'' (2007)
Songs
* "Don't" (Bill ...
'.
* In ''
The Myth of Sisyphus'' the French existentialist
Albert Camus
Albert Camus ( , ; ; 7 November 1913 – 4 January 1960) was a French philosopher, author, dramatist, and journalist. He was awarded the 1957 Nobel Prize in Literature at the age of 44, the second-youngest recipient in history. His work ...
comments that the age of thirty is a crucial period in the life of a man, for at that age he gains a new awareness of the meaning of time.
* In
Franz Kafka
Franz Kafka (3 July 1883 – 3 June 1924) was a German-speaking Bohemian novelist and short-story writer, widely regarded as one of the major figures of 20th-century literature. His work fuses elements of realism and the fantastic. It ...
's novel ''The Trial'' Joseph wakes up on the morning of his thirtieth birthday to find himself under arrest for an unspecified crime. After making many futile attempts to find the nature of the crime or the name of his accuser, Joseph dies on the eve of his thirty-first birthday.
* The number of uprights that formed the
Sarsen Circle
Sarsen stones are silicified sandstone blocks found in quantity in Southern England on Salisbury Plain and the Marlborough Downs in Wiltshire; in Kent; and in smaller quantities in Berkshire, Essex, Oxfordshire, Dorset, and Hampshire.
Geology ...
at
Stonehenge
Stonehenge is a prehistoric monument on Salisbury Plain in Wiltshire, England, west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around high, wide, and weighing around 25 tons, topped by connectin ...
, also the supposed number of holes forming the arrays of
Y and Z Holes
The Y and Z Holes are two rings of concentric (though irregular) circuits of 30 and 29 near-identical pits cut around the outside of the Sarsen Circle at Stonehenge. The current view is that both circuits are contemporary. Radiocarbon d ...
at Stonehenge.
* Western Christianity's most prolific 20th-century essayist,
F. W. Boreham
Frank William Boreham OBE (3 March 1871, Tunbridge Wells, Kent, England – 18 May 1959, Melbourne, Victoria) was a Baptist preacher best known in New Zealand, Australia, and England.
Life and career
Boreham's birth coincided with the end of the ...
in 'Life at Thirty' ('Cliffs of Opal') mentions that in addition to Jesus commencing ministry at 30 (Luke 3:23), Joseph was 30 when he stood before Pharaoh, King of Egypt (Genesis 41:46), King David was 30 when he began to reign (2 Samuel 5:4), and the Levites were numbered from the age of 30 and upward (1 Chronicles 23:3). Also in that essay Boreham writes 'It was said of
he English poet
He or HE may refer to:
Language
* He (pronoun), an English pronoun
* He (kana), the romanization of the Japanese kana へ
* He (letter), the fifth letter of many Semitic alphabets
* He (Cyrillic), a letter of the Cyrillic script called ''He'' ...
Keats, that "he ensphered himself in thirty perfect years and died, not young".'
Sports
* In tennis, the number 30 represents the second point gained in a game.
* In baseball, 30 is the number of teams in
Major League Baseball
Major League Baseball (MLB) is a professional baseball organization and the oldest major professional sports league in the world. MLB is composed of 30 total teams, divided equally between the National League (NL) and the American League (AL), ...
.
* In basketball, there are 30 teams in the
National Basketball Association
The National Basketball Association (NBA) is a professional basketball league in North America. The league is composed of 30 teams (29 in the United States and 1 in Canada) and is one of the major professional sports leagues in the United S ...
.
Music
* The number of variations in Bach's
Goldberg Variations
* ''
30'', a 2001 album by Harry Connick, Jr.
*
Thirty Seconds to Mars
Thirty Seconds to Mars (commonly stylized as 30 Seconds to Mars) is an American rock band from Los Angeles, California, formed in 1998. The band consists of brothers Jared Leto (lead vocals, guitar, bass, keyboards) and Shannon Leto (drums, pe ...
, an American rock band
* "
30 Minutes", a song by t.A.T.u
* ''
Thirty'', a 2013 album by Anthony Callea
* ''
XXX
XXX may refer to:
Codes and symbols
* 30 (number), Roman numeral XXX
* XXX, designating pornography
** XXX, an X rating#United_States, X rating
** .xxx, an internet top-level domain intended for pornographic sites
* XXX, a symbol of the straight ...
'', an album by Danny Brown
* ''
30'', a 2021 album by Adele
See also
*
List of highways numbered 30
References
{{DEFAULTSORT:30 (Number)
Integers