129 (one hundred ndtwenty-nine) 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 ...

following 128 and preceding 130.

In mathematics

129 is the sum of the first ten prime numbers. It is the smallest number that can be expressed as a sum of three squares in four different ways:

11^2+2^2+2^2

10^2+5^2+2^2

8^2+8^2+1^2

, and

8^2+7^2+4^2

. 129 is the product of only two primes, 3 and 43, making 129 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 ...

. Since 3 and 43 are both

Gaussian prime In number theory, a Gaussian integer is a complex number whose real and imaginary parts are both integers. The Gaussian integers, with ordinary addition and multiplication of complex numbers, form an integral domain, usually written as \mathbf /ma ...

s, this means that 129 is a

Blum integer In mathematics, a natural number ''n'' is a Blum integer if is a semiprime for which ''p'' and ''q'' are distinct prime numbers congruent to 3 mod 4.Joe Hurd, Blum Integers (1997), retrieved 17 Jan, 2011 from http://www.gilith.com/research/tal ...

. 129 is a

repdigit In recreational mathematics, a repdigit or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system (often implicitly decimal). The word is a portmanteau of repeated and digit. Example ...

in base 6 (333). 129 is a

happy number In number theory, a happy number is a number which eventually reaches 1 when replaced by the sum of the square of each digit. For instance, 13 is a happy number because 1^2+3^2=10, and 1^2+0^2=1. On the other hand, 4 is not a happy number because ...

. 129 is a

centered octahedral number A centered octahedral number or Haüy octahedral number is a figurate number that counts the number of points of a three-dimensional integer lattice that lie inside an octahedron centered at the origin. The same numbers are special cases of t ...

In the military

* Raytheon AGM-129 ACM (Advanced Cruise Missile) was a low observable, sub-sonic, jet-powered, air-launched cruise missile used by the United States Air Force * Soviet submarine K-129 (1960) was a

Soviet Pacific Fleet , image = Great emblem of the Pacific Fleet.svg , image_size = 150px , caption = Russian Pacific Fleet Great emblem , dates = 1731–present , country ...

nuclear submarine that sank in 1968 * was a United States Navy ''Mission Buenaventura''-class fleet oilers during World War II * was a ''Crosley-class high speed transport of the United States Navy * was the lead ship of her class of destroyer escort in the United States Navy * was a United States Navy ''Haskell''-class attack transport during World War II * was a United States Navy ''Crater''-class cargo ship during World War II * was a United States Navy ''Auk''-class minesweeper for removing naval mines laid in the water *

Agusta A129 Mangusta The Agusta A129 Mangusta ( en, Mongoose) is an attack helicopter originally designed and produced by Italian company Agusta. It is the first attack helicopter to be designed and produced wholly in Europe. It has continued to be developed by Agus ...

is an attack helicopter originally designed and produced by Italian company Agusta * The 129th Rescue Wing (129 RQW) is a unit of the California Air National Guard

In transportation

LZ 129 Hindenburg LZ 129 ''Hindenburg'' (; Registration: D-LZ 129) was a German commercial passenger-carrying rigid airship, the lead ship of the ''Hindenburg'' class, the longest class of flying machine and the largest airship by envelope volume. It was desi ...

was a German zeppelin which went up in flames while landing on May 6, 1937 *

London Buses route 129 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 London, G ...

is a Transport for London contracted bus route in London *

STS-129 STS-129 (ISS assembly sequence, ISS assembly flight ULF3) was a NASA Space Shuttle mission to the International Space Station (ISS). ''Space Shuttle Atlantis, Atlantis'' was launched on November 16, 2009 at 14:28 Eastern Time Zone, EST, and land ...

was a Space Shuttle mission to the International Space Station, flown in November 2009 by the shuttle ''Atlantis''.

In other fields

129 is also: * The year

AD 129 Advertising is the practice and techniques employed to bring attention to a product or service. Advertising aims to put a product or service in the spotlight in hopes of drawing it attention from consumers. It is typically used to promote a ...

129 BC __NOTOC__ Year 129 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Tuditanus and Aquillius (or, less frequently, year 625 ''Ab urbe condita'') and the Sixth Year of Yuanguang. The denomin ...

* 129 AH is a year in the Islamic calendar that corresponds to 746– 747 CE * 129 Antigone is a main belt asteroid * The atomic number of unbiennium, an element yet to be discovered *A film format: 129 film * Sonnet 129 by William Shakespeare

References

{{Integers, 1 Integers

In mathematics

In the military

In transportation

In other fields

See also

References