251 (number)
Encyclopedia
251 is the natural number between 250
and 252. It is also a prime number
.
, a Chen prime
, a Gaussian prime, a Sophie Germain prime
, and a sexy prime
.
251 is also sum of three consecutive primes (79 + 83 + 89) and sum of seven consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47).
251 is also the smallest number that can be written as the sum of three cubes in two ways: 251 = 13 + 53 + 53 = 23 + 33 + 63.
250 (number)
250 is the natural number following 249 and preceding 251.As a Mandarin slang term, 250 is an insult meaning "stupid person" or "simpleton". The expression is based on bàndiàozi...
and 252. It is also a prime number
Prime number
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2...
.
| Ordinal Ordinal number In set theory, an ordinal number, or just ordinal, is the order type of a well-ordered set. They are usually identified with hereditarily transitive sets. Ordinals are an extension of the natural numbers different from integers and from cardinals... | Two hundred [and] fifty-one |
| Cardinal Cardinal number In mathematics, cardinal numbers, or cardinals for short, are a generalization of the natural numbers used to measure the cardinality of sets. The cardinality of a finite set is a natural number – the number of elements in the set. The transfinite cardinal numbers describe the sizes of infinite... |
251st |
| Factorization Factorization In mathematics, factorization or factoring is the decomposition of an object into a product of other objects, or factors, which when multiplied together give the original... |
prime number Prime number A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2... |
In mathematics
251 is a regular prime, an Eisenstein primeEisenstein prime
In mathematics, an Eisenstein prime is an Eisenstein integerz = a + b\,\omega\qquadthat is irreducible in the ring-theoretic sense: its only Eisenstein divisors are the units , a + bω itself and its associates.The associates and the complex conjugate...
, a Chen prime
Chen prime
A prime number p is called a Chen prime if p + 2 is either a prime or a product of two primes. The even number 2p + 2 therefore satisfies Chen's theorem....
, a Gaussian prime, a Sophie Germain prime
Sophie Germain prime
In number theory, a prime number p is a Sophie Germain prime if 2p + 1 is also prime. For example, 23 is a Sophie Germain prime because it is a prime and 2 × 23 + 1 = 47, and 47 is also a prime number...
, and a sexy prime
Sexy prime
In mathematics, a sexy prime is a prime number that differs from another prime number by six. For example, the numbers 5 and 11 are both sexy primes, because they differ by 6...
.
251 is also sum of three consecutive primes (79 + 83 + 89) and sum of seven consecutive primes (23 + 29 + 31 + 37 + 41 + 43 + 47).
251 is also the smallest number that can be written as the sum of three cubes in two ways: 251 = 13 + 53 + 53 = 23 + 33 + 63.
In other fields
- 2-5-1 is a common chord progressionChord progressionA chord progression is a series of musical chords, or chord changes that "aims for a definite goal" of establishing a tonality founded on a key, root or tonic chord. In other words, the succession of root relationships...
in jazzJazzJazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...
musicMusic theoryMusic theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers' techniques across or within genres, styles, or historical periods...
. - Vermont 251 ClubVermont 251 ClubThe Vermont 251 Club is an organization whose members attempt to visit all 251 towns and cities in Vermont. Those who visit all 251 are known as "plus members."-History:...
is a club in which members try to visit each of the 251 towns and cities of VermontVermontVermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...
. - The number of PokémonPokémonis a media franchise published and owned by the video game company Nintendo and created by Satoshi Tajiri in 1996. Originally released as a pair of interlinkable Game Boy role-playing video games developed by Game Freak, Pokémon has since become the second most successful and lucrative video...
available in Pokémon Gold and SilverPokémon Gold and Silverare the second installments of the Pokémon series of role-playing video games developed by Game Freak and published by Nintendo for the Game Boy Color. The games have dual-mode capabilities allowing them to also be played on earlier Game Boy models. They were first released in Japan in 1999 and to...
is 251 - 251 is a title of a play based on Annabel ChongAnnabel ChongGrace Quek , better known by her stage name Annabel Chong, is a former pornographic actress now living in the United States. On 19 January 1995, at the age of 22, she became famous by engaging in 251 sex acts with about 70 men over a ten-hour period, setting a world record, with the resulting...
story, who became famous for engaging in 251 sex acts over a ten hour period in January 1995, setting a world record as the world's biggest gang bang. - The 251ALCO 251The Alco 251 diesel engine was developed by the American Locomotive Company to replace the 244 and 539. The 251 was developed to be used in diesel locomotives, as a marine power plant in ships and as a stationary power generator.-Development:...
is the last and most powerful prime mover (engine) designed and built by the American Locomotive CompanyAmerican Locomotive CompanyThe American Locomotive Company, often shortened to ALCO or Alco , was a builder of railroad locomotives in the United States.-Early history:...
(ALCO). It was available in 12- and 16-cylinder versions, along with a single experimental 18-cylinder variant. The 251 was produced from 1949 until ALCO left the locomotive business in 1969. The design is still currently produced by Fairbanks-MorseFairbanks-MorseFairbanks Morse and Company was a manufacturing company in the late 19th and early 20th century. Originally a weighing scale manufacturer, it later diversified into pumps, engines, windmills, locomotives and industrial supplies until it was merged in 1958...
.