127 (one hundred ndtwenty-seven) 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 126 and preceding 128. It is also a prime number.

In mathematics

*As a

Mersenne prime In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form for some integer . They are named after Marin Mersenne, a French Minim friar, who studied them in the early 17t ...

, 127 is related to the

perfect number In number theory, a perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. For instance, 6 has divisors 1, 2 and 3 (excluding itself), and 1 + 2 + 3 = 6, so 6 is a perfect number. T ...

8128. 127 is also the largest known mersenne prime exponent for a Mersenne number,

2^-1

, which is also a Mersenne prime. It was discovered by

Édouard Lucas __NOTOC__ François Édouard Anatole Lucas (; 4 April 1842 – 3 October 1891) was a French mathematician. Lucas is known for his study of the Fibonacci sequence. The related Lucas sequences and Lucas numbers are named after him. Biography Lucas ...

in 1876 and held the record for the

largest known prime The largest known prime number () is , a number which has 24,862,048 digits when written in base 10. It was found via a computer volunteered by Patrick Laroche of the Great Internet Mersenne Prime Search (GIMPS) in 2018. A prime number is a posi ...

for 75 years. **

2^-1

is the largest prime ever discovered by hand calculations as well as the largest known

double Mersenne prime In mathematics, a double Mersenne number is a Mersenne number of the form :M_ = 2^-1 where ''p'' is prime. Examples The first four terms of the sequence of double Mersenne numbers areChris Caldwell''Mersenne Primes: History, Theorems and ...

. ** Furthermore, 127 is equal to

2^-1

, and 7 is equal to

2^-1

, and 3 is the smallest Mersenne prime, making 7 the smallest double Mersenne prime and 127 the smallest triple Mersenne prime. *There are a total of 127

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 between 2,000 and 3,000. *127 is also a

cuban prime A cuban prime is a prime number that is also a solution to one of two different specific equations involving differences between third powers of two integers ''x'' and ''y''. First series This is the first of these equations: :p = \frac,\ x = ...

of the form

p=\frac

x=y+1

. The next prime is 131, with which it comprises a

cousin prime In number theory, cousin primes are prime numbers that differ by four. Compare this with twin primes, pairs of prime numbers that differ by two, and sexy primes, pairs of prime numbers that differ by six. The cousin primes (sequences and in O ...

. Because the next

odd number In mathematics, parity is the property of an integer of whether it is even or odd. An integer is even if it is a multiple of two, and odd if it is not.. For example, −4, 0, 82 are even because \begin -2 \cdot 2 &= -4 \\ 0 \cdot 2 &= 0 \\ 41 ...

, 129, is a

semiprime In mathematics, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other, so the semiprimes include the squares of prime numbers. Because there are infinitely many prime nu ...

, 127 is a

Chen prime A prime number ''p'' is called a Chen prime if ''p'' + 2 is either a prime or a product of two primes (also called a semiprime). The even number 2''p'' + 2 therefore satisfies Chen's theorem. The Chen primes are named after Chen Jingru ...

. 127 is greater than the arithmetic mean of its two neighboring primes; thus, it is a strong prime. *127 is a

centered hexagonal number In mathematics and combinatorics, a centered hexagonal number, or hex number, is a centered figurate number that represents a hexagon with a dot in the center and all other dots surrounding the center dot in a hexagonal lattice. The following ...

. *It is the seventh

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 ...

. *127 is a palindromic prime in

nonary A ternary numeral system (also called base 3 or trinary) has 3 (number), three as its radix, base. Analogous to a bit, a ternary numerical digit, digit is a trit (trinary digit). One trit is equivalent to binary logarithm, log2 3 (about 1.5 ...

and

binary Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that ta ...

. *127 is the first Friedman prime in decimal. It is also the first nice Friedman number in decimal, since

127=2^-1 \,

, as well as binary since

1111111 = (1 + 1)^ - 1 \,

. *127 is the sum of the sums of the divisors of the first twelve

positive integers 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 ...

. *127 is the smallest prime that can be written as the sum of the first two or more odd primes:

127 = 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29

. *127 is the smallest odd number that cannot be written in the form

p+2^

, for is a

, and is an

integer An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign (−1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the language ...

, since 127 - 2⁰ = 126, 127 - 2¹ = 125, 127 - 2² = 123, 127 - 2³ = 119, 127 - 2⁴ = 111, 127 - 2⁵ = 95, and 127 - 2⁶ = 63 are all

composite number A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Equivalently, it is a positive integer that has at least one divisor other than 1 and itself. Every positive integer is composite, prime, ...

s. *127 is an isolated prime where neither p-2 nor p+2 are prime. *127 is the smallest digitally delicate prime in binary. *127 is the 31st prime number and therefore it is the smallest

with a Mersenne prime index. *127 is the largest number with the property 127 = 1*prime(1) + 2*prime(2) + 7*prime(7). Where prime(n) is the n-th prime number. There are only two numbers with that property, the other one is 43. *127 is the number of different ways in which 10,000 can be expressed as the sum of two prime numbers.

In the military

* was a ''Mission Buenaventura''-class

fleet oilers A replenishment oiler or replenishment tanker is a naval auxiliary ship with fuel tanks and dry cargo holds which can supply both fuel and dry stores during underway replenishment (UNREP) at sea. Many countries have used replenishment oilers. The ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

* was a

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land ( rail and road), water, cable, pipelin ...

ship * was a United States Navy * was a United States Navy in World War II * was a United States Navy * was a United States Navy for removing naval mines

In religion

* The biblical figure Sarah died at the age of 127. * According to the Book of , the

Persian Empire The Achaemenid Empire or Achaemenian Empire (; peo, wikt:𐎧𐏁𐏂𐎶, 𐎧𐏁𐏂, , ), also called the First Persian Empire, was an History of Iran#Classical antiquity, ancient Iranian empire founded by Cyrus the Great in 550 BC. Bas ...

under

Ahasuerus Ahasuerus ( ; , commonly ''Achashverosh'';; fa, اخشورش, Axšoreš; fa, label= New Persian, خشایار, Xašāyār; grc, Ξέρξης, Xérxēs. grc, label= Koine Greek, Ἀσουήρος, Asouḗros, in the Septuagint; la, Assue ...

contained 127 provinces * Havamal

Stanza In poetry, a stanza (; from Italian language, Italian ''stanza'' , "room") is a group of lines within a poem, usually set off from others by a blank line or Indentation (typesetting), indentation. Stanzas can have regular rhyme scheme, rhyme and ...

127 is used as a declaration against folkish traditions of Heathenry and specifically the Asatru Folk Assembly.

In transportation

* The small

Fiat 127 The Fiat 127 is a supermini car produced by Italian car manufacturer FIAT from 1971 to 1983. It was introduced in 1971 as the replacement for the Fiat 850. Production of the 127 in Italy ended in 1983 following the introduction of its replacemen ...

automobile *

London Buses route 127 This is a list of Transport for London (TfL) contracted bus routes in London, England, as well as commercial services that enter the Greater London area (except coaches). Bus services in London are operated by Abellio London, Arriva Londo ...

is a Transport for London contracted bus route in

London London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...

* 127 is the number of many roads, including

U.S. Route 127 U.S. Route 127 (US 127) is a north–south U.S. Highway in the eastern half of the United States. The southern terminus of the route is at US 27 in Chattanooga, Tennessee. The northern terminus is at Interstate 75 (I-75) near G ...

STS-127 STS-127 ( ISS assembly flight 2J/A) was a NASA Space Shuttle mission to the International Space Station (ISS). It was the twenty-third flight of . The primary purpose of the STS-127 mission was to deliver and install the final two components of t ...

was a Space Shuttle ''Endeavour'' mission to the

International Space Station The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...

which launched on June 15, 2009

In other fields

* '' 127 Hours'' is a film released in 2010 * The year

AD 127 Year 127 ( CXXVII) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Rufus and Squilla (or, less frequently, year 880 '' Ab urbe condi ...

or 127 BC * 127 AH is a year in the

Islamic calendar The Hijri calendar ( ar, ٱلتَّقْوِيم ٱلْهِجْرِيّ, translit=al-taqwīm al-hijrī), also known in English as the Muslim calendar and Islamic calendar, is a lunar calendar consisting of 12 lunar months in a year of 354 ...

that corresponds to

744 __NOTOC__ Year 744 ( DCCXLIV) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. The denomination 744 for this year has been used since the early medieval period, when the Anno Domini calendar e ...

–

745 __NOTOC__ Year 745 ( DCCXLV) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. The denomination 745 for this year has been used since the early medieval period, when the Anno Domini calendar era ...

CE * 127 Johanna, a Main belt asteroid * 127 film, a film format * 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 ...

Unbiseptium An extended periodic table theorises about chemical elements beyond those currently known in the periodic table and proven. , the element with the highest atomic number known is oganesson (''Z'' = 118), which completes the seventh period (row ...

, an element that has not yet been discovered * The LZ 127 ''Graf Zeppelin'', a dirigible *

Sonnet 127 Sonnet 127 of '' Shakespeare's sonnets'' (1609) is the first of the Dark Lady sequence (sonnets 127–152), called so because the poems make it clear that the speaker's mistress has black hair and eyes and dark skin. In this poem the speaker fi ...

William Shakespeare William Shakespeare ( 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's nation ...

127th Street Ensemble Tupac Amaru Shakur ( ; born Lesane Parish Crooks, June 16, 1971 – September 13, 1996), also known as 2Pac and Makaveli, was an American rapper. He is widely considered one of the most influential rappers of all time. Shakur is among the b ...

was a troupe of

African-American African Americans (also referred to as Black Americans and Afro-Americans) are an Race and ethnicity in the United States, ethnic group consisting of Americans with partial or total ancestry from sub-Saharan Africa. The term "African American ...

actors which included

Tupac Amaru Shakur Tupac Amaru Shakur ( ; born Lesane Parish Crooks, June 16, 1971 – September 13, 1996), also known as 2Pac and Makaveli, was an American rapper. He is widely considered one of the most influential rappers of all time. Shakur is among the b ...

NCT 127 NCT 127 () is the first fixed and second overall sub-unit of the South Korean boy band NCT, formed and managed by SM Entertainment. The current lineup consists of nine active members: Taeil, Johnny, Taeyong, Yuta, Doyoung, Jaehyun, Jungwo ...

, K-pop boy group under SM Entertainment * In IP (Internet Protocol) Version 4, it is the last Class A network and is also the subnet used for loopback functionality in computer networking * The highest signed 8-bit integer, using

two's complement Two's complement is a mathematical operation to reversibly convert a positive binary number into a negative binary number with equivalent (but negative) value, using the binary digit with the greatest place value (the leftmost bit in big- endian ...

* The non-printable " Delete" (DEL) control character in

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...

. * Linotype (and Intertype) machines used brass matrices with one of 127 possible combinations punched into the top to enable the matrices to return to their proper channel in the magazine. * 127 is the smallest positive integer, ''n'', such that ''n'' centimeters is a whole number of inches. 127 cm is exactly 50 inches.

References

* Wells, D. ''

The Penguin Dictionary of Curious and Interesting Numbers ''The Penguin Dictionary of Curious and Interesting Numbers'' is a reference book for recreational mathematics and elementary number theory written by David Wells. The first edition was published in paperback by Penguin Books in 1986 in the UK, ...