51 (fifty-one) 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
50 and preceding
52.
In mathematics
Fifty-one is
* a
pentagonal number
A pentagonal number is a figurate number that extends the concept of triangular and square numbers to the pentagon, but, unlike the first two, the patterns involved in the construction of pentagonal numbers are not rotationally symmetrical. The ...
as well as a
centered pentagonal number
A centered pentagonal number is a centered figurate number that represents a pentagon with a dot in the center and all other dots surrounding the center in successive pentagonal layers. The centered pentagonal number for ''n'' is given by the ...
and an 18-gonal number
*the 6th
Motzkin number
In mathematics, the th Motzkin number is the number of different ways of drawing non-intersecting chords between points on a circle (not necessarily touching every point by a chord). The Motzkin numbers are named after Theodore Motzkin and have d ...
, telling the number of ways to draw non-intersecting
chords
Chord may refer to:
* Chord (music), an aggregate of musical pitches sounded simultaneously
** Guitar chord a chord played on a guitar, which has a particular tuning
* Chord (geometry), a line segment joining two points on a curve
* Chord ( ...
between any six points on a circle's boundary, no matter where the points may be located on the boundary.
*a
Perrin number
In mathematics, the Perrin numbers are defined by the recurrence relation
: for ,
with initial values
:.
The sequence of Perrin numbers starts with
: 3, 0, 2, 3, 2, 5, 5, 7, 10, 12, 17, 22, 29, 39, ...
The number of different maxima ...
., coming after 22, 29, 39 in the sequence (and the sum of the first two)
* a
Størmer number In mathematics, a Størmer number or arc-cotangent irreducible number is a positive integer n for which the greatest prime factor of n^2+1 is greater than or equal to 2n. They are named after Carl Størmer.
Sequence
The first few Størmer numbers ...
, since the greatest prime factor of 51
2 + 1 = 2602 is 1301, which is substantially more than 51 twice.
*There are 51 different
cyclic
Cycle, cycles, or cyclic may refer to:
Anthropology and social sciences
* Cyclic history, a theory of history
* Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr.
* Social cycle, various cycles in s ...
Gilbreath permutation A Gilbreath shuffle is a way to shuffle a deck of cards, named after mathematician Norman Gilbreath (also known for Gilbreath's conjecture).
Gilbreath's principle describes the properties of a deck that are preserved by this type of shuffle, and ...
s on 10 elements, and therefore there are 51 different
real
Real may refer to:
Currencies
* Brazilian real (R$)
* Central American Republic real
* Mexican real
* Portuguese real
* Spanish real
* Spanish colonial real
Music Albums
* ''Real'' (L'Arc-en-Ciel album) (2000)
* ''Real'' (Bright album) (2010) ...
periodic points of order 10 on the
Mandelbrot set
The Mandelbrot set () is the set of complex numbers c for which the function f_c(z)=z^2+c does not diverge to infinity when iterated from z=0, i.e., for which the sequence f_c(0), f_c(f_c(0)), etc., remains bounded in absolute value.
This ...
.
[.]
*Since 51 is the product of the distinct
Fermat prime
In mathematics, a Fermat number, named after Pierre de Fermat, who first studied them, is a positive integer of the form
:F_ = 2^ + 1,
where ''n'' is a non-negative integer. The first few Fermat numbers are:
: 3, 5, 17, 257, 65537, 429496 ...
s 3 and 17, a
regular polygon
In Euclidean geometry, a regular polygon is a polygon that is Equiangular polygon, direct equiangular (all angles are equal in measure) and Equilateral polygon, equilateral (all sides have the same length). Regular polygons may be either convex p ...
with 51 sides is
constructible with compass and straightedge, the angle is constructible, and the number
cos is
expressible in terms of square roots.
In other fields
51 is:
*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
antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient time ...
* The code for international direct dial phone calls to
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
* The last possible
television channel
A television channel is a terrestrial frequency or virtual number over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the terrestrial or cable band of 54 to 60 MHz, with ...
number in the
UHF bandplan for American terrestrial television from December 31, 2011, when channels 5269 were withdrawn, to July 3, 2020,
when channels 38—51 were removed from the bandplan.
*The number of the laps of the
Azerbaijan Grand Prix.
* In the 2006 film ''
Cars
A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods.
The year 1886 is regarded as t ...
'', 51 was
Doc Hudson
Doctor Hudson Hornet, MD (also known as The Fabulous Hudson Hornet, Hud, Doc Hudson, or simply, Doc) is an animated, anthropomorphic retired race car which appears in the 2006 Pixar film ''Cars'' as a medical doctor and a local judge. He is ...
's number.
* The
Area 51
Area 51 is the common name of a highly classified United States Air Force (USAF) facility within the Nevada Test and Training Range. A remote detachment administered by Edwards Air Force Base, the facility is officially called Homey Airport ...
.
* The fire station number in the television series ''
Emergency!
''Emergency!'' is an American action-adventure medical drama television series jointly produced by Mark VII Limited and Universal Television. Debuting on NBC as a midseason replacement on January 15, 1972, replacing the two short-lived situatio ...
''.
* The number of essays
Alexander Hamilton
Alexander Hamilton (January 11, 1755 or 1757July 12, 1804) was an American military officer, statesman, and Founding Father who served as the first United States secretary of the treasury from 1789 to 1795.
Born out of wedlock in Charlest ...
wrote as part of ''The Federalist Papers'' defending the US constitution
See also
*
AD 51
AD 51 ( LI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Caesar and Scipio (or, less frequently, year 804 ''Ab urbe condita''). Th ...
, a year in the
Julian calendar
The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandr ...
*
List of highways numbered 51
The following highways are numbered 51:
Australia
* Kamilaroi Highway
* Plenty Road
Cambodia
*National Road 51 (Cambodia)
Canada
* Alberta Highway 51 (defunct)
* Saskatchewan Highway 51
Finland
* Finnish national road 51
France
*A51 autorout ...
* The model number of the
P-51 Mustang
The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in April 1940 by a team headed by James ...
World War II fighter aircraft
*
Area 51
Area 51 is the common name of a highly classified United States Air Force (USAF) facility within the Nevada Test and Training Range. A remote detachment administered by Edwards Air Force Base, the facility is officially called Homey Airport ...
, a parcel of U.S. military-controlled land in southern Nevada, apparently containing a secret aircraft testing facility
* ''
Photo 51 '
''Photo 51'' is an X-ray based fiber diffraction image of a paracrystalline gel composed of DNA fiber taken by Raymond Gosling, a graduate student working under the supervision of Rosalind Franklin in May 1952 at King's College London, wh ...
'', an X-ray image of key importance in elucidating the structure of DNA in the 1950s
* ''
Fifty-One Tales
''Fifty-One Tales'' is a collection of fantasy short stories by Irish writer Lord Dunsany, considered a major influence on the work of J. R. R. Tolkien, H. P. Lovecraft, Ursula K. Le Guin and others. The first editions, in hardcover, were publi ...
'', part of the title of a collection of stories by Lord Dunsany
* "
51st State", any future US state, usually referring to Washington D.C. or Puerto Rico. Occasionally used in commentary to refer to non-US entities (such as
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
) adopting US-like policies or seeking to become part of the US.
*
''51'' (film), a 2011 American horror film
* "
Fifty-One
"Fifty-One" is the fourth episode of the fifth season of the American television crime drama series ''Breaking Bad'', and the 50th overall episode of the series. Written by Sam Catlin and directed by Rian Johnson, it originally aired on AMC in ...
", an episode of ''Breaking Bad''
*
Pastis 51
Pastis (; oc, Pastís, ; or ) is an anise-flavoured spirit and apéritif traditionally from France, typically containing less than 100 g/L sugar and 40–45% ABV (alcohol by volume).
Origins
Pastis was first commercialized by Paul Ricard in ...
, often just called "51", is a brand of pastis owned by
Pernod Ricard.
*
Greg Murphy used "#51" for most of the seasons he raced in
V8 Supercars
The Supercars Championship is a touring car racing category in Australia, running as an International Series under Fédération Internationale de l'Automobile (FIA) regulations, governing the sport.
Supercars events take place in all Australian ...
*''
Clubhouse Games: 51 Worldwide Classics'', a Nintendo Switch video game with fifty-one activities
References
{{Integers, zero
Integers