127 (number)

From Wikipedia, the free encyclopedia
← 126 127 128 →
← 120 121 122 123 124 125 126 127 128 129 →
List of numbers — Integers
← 0 100 200 300 400 500 600 700 800 900 →
Cardinalone hundred twenty-seven
Ordinal127th
(one hundred twenty-seventh)
Factorizationprime
Prime31st
Divisors1, 127
Greek numeralΡΚΖ´
Roman numeralCXXVII
Binary11111112
Ternary112013
Octal1778
DuodecimalA712
Hexadecimal7F16

127 (one hundred [and] twenty-seven) is the natural number following 126 and preceding 128. It is also a prime number.

In mathematics[]

  • As a Mersenne prime, 127 is related to the perfect number 8128. 127 is also an exponent for another Mersenne prime 2127 - 1, which was discovered by Édouard Lucas in 1876, and held the record for the largest known prime for 75 years.
    • 2127 - 1 is the largest prime ever discovered by hand calculations, as well as the largest known double Mersenne prime.
    • Furthermore, 127 is equal to 27 - 1, and 7 is equal to 23 - 1, and 3 is the smallest Mersenne prime, this makes 7 the smallest double Mersenne prime and 127 the smallest triple Mersenne prime.
  • There are a total of 127 prime numbers between 2,000 and 3,000.
  • 127 is also a cuban prime of the form , .[1] The next prime is 131, with which it comprises a cousin prime. Because the next odd number, 129, is a semiprime, 127 is a Chen prime. 127 is greater than the arithmetic mean of its two neighboring primes, thus it is a strong prime.[2]
  • 127 is a centered hexagonal number.[3]
  • It is the 7th Motzkin number.[4]
  • 127 is a palindromic prime in nonary and binary.
  • 127 is the first Friedman prime in base 10. It is also the first nice Friedman number in base 10, since , as well as binary since .
  • 127 is the sum of the sums of the divisors of the first 12 positive integers.[5]
  • 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.[6]
  • 127 is the smallest odd number that can't be written in the form p + 2x for p=prime number and x=integer, 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 numbers.[7]
  • 127 is an isolated prime where neither p-2 nor p+2 are prime.
  • 127 is the smallest digitally delicate prime in base 2.[8]
  • 127 is the 31st prime number and therefore it is the smallest Mersenne prime with a Mersenne prime index.

In the military[]

  • USNS Mission San Luis Obispo (T-AO-127) was a Mission Buenaventura-class fleet oilers during World War II
  • USS Admiral W. S. Sims (AP-127) was a United States Navy transport ship
  • USS Allendale (APA-127) was a United States Navy Haskell-class attack transport
  • USS Alnitah (AK-127) was a United States Navy Crater-class cargo ship in World War II
  • USS Raccoon (IX-127) was a United States Navy Armadillo-class tanker
  • USS Tumult (AM-127) was a United States Navy Auk-class minesweeper for removing naval mines

In religion[]

  • The biblical figure Sarah died at the age of 127.[9]
  • According to the Book of Esther 1:1, the Persian Empire under Ahasuerus contained 127 provinces
  • Havamal Stanza 127 is used as a declaration against folkish traditions of Heathenry and specifically the Asatru Folk Assembly.[10]

In transportation[]

  • The small Fiat 127 automobile
  • London Buses route 127 is a Transport for London contracted bus route in London
  • 127 is the number of many roads, including U.S. Route 127
  • STS-127 was a Space Shuttle Endeavour mission to the International Space Station which launched on June 15, 2009

In other fields[]

127 is also:

  • 127 Hours is a film released in 2010
  • The year AD 127 or 127 BC
  • 127 AH is a year in the Islamic calendar that corresponds to 744 – 745 CE
  • 127 Johanna, a Main belt asteroid
  • 127 film, a film format
  • The atomic number of Unbiseptium, an element that has not yet been discovered
  • The LZ 127 Graf Zeppelin, a dirigible
  • Sonnet 127 by William Shakespeare
  • 127th Street Ensemble was a troupe of African-American actors which included Tupac Amaru Shakur
  • NCT 127, 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
  • The non-printable "Delete" (DEL) control character in ASCII.

See also[]

References[]

  1. ^ "Sloane's A002407 : Cuban primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  2. ^ "Sloane's A051634 : Strong primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  3. ^ "Sloane's A003215 : Hex (or centered hexagonal) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  4. ^ "Sloane's A001006 : Motzkin numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  5. ^ Sloane, N. J. A. (ed.). "Sequence A024916 (sum_{k=1..n} sigma(k) where sigma(n) = sum of divisors of n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  6. ^ Sloane, N. J. A. (ed.). "Sequence A071148". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.. Partial sums of sequence of odd primes; a(n) = sum of the first n odd primes.
  7. ^ Sloane, N. J. A. (ed.). "Sequence A006285 (Odd numbers not of form p + 2^x (de Polignac numbers))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  8. ^ Sloane, N. J. A. (ed.). "Sequence A137985". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.. Complementing any single bit in the binary representation of these primes produces a composite number.
  9. ^ "Sara". Catholic Encyclopedia. Retrieved September 8, 2015.
  10. ^ "Declaration 127".
  • Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 136 - 138
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