131 (number)
| ||||
|---|---|---|---|---|
| Cardinal | one hundred thirty-one | |||
| Ordinal | 131st (one hundred thirty-first) | |||
| Factorization | prime | |||
| Prime | 32nd | |||
| Divisors | 1, 131 | |||
| Greek numeral | ΡΛΑ´ | |||
| Roman numeral | CXXXI | |||
| Binary | 100000112 | |||
| Ternary | 112123 | |||
| Senary | 3356 | |||
| Octal | 2038 | |||
| Duodecimal | AB12 | |||
| Hexadecimal | 8316 | |||
131 (one hundred [and] thirty-one) is the natural number following 130 and preceding 132.
In mathematics
[edit]131 is a Sophie Germain prime,[1] an irregular prime,[2] the second 3-digit palindromic prime, and also a permutable prime with 113 and 311. It can be expressed as the sum of three consecutive primes, 131 = 41 + 43 + 47. 131 is an Eisenstein prime with no imaginary part and real part of the form . Because the next odd number, 133, is a semiprime, 131 is a Chen prime. 131 is an Ulam number.[3]
131 is a full reptend prime in base 10 (and also in base 2). The decimal expansion of 1/131 repeats the digits 007633587786259541984732824427480916030534351145038167938931 297709923664122137404580152671755725190839694656488549618320 6106870229 indefinitely.
131 is the fifth discriminant of imaginary quadratic fields with class number 5, where the 131st prime number 739 is the fifteenth such discriminant.[4] Meanwhile, there are conjectured to be a total of 131 discriminants of class number 8 (only one more discriminant could exist).[5]
In the military
[edit]- Convair C-131 Samaritan was an American military transport produced from 1954 to 1956
- Strike Fighter Squadron (VFA-131) is a United States Navy F/A-18C Hornet fighter squadron stationed at Naval Air Station Oceana
- Tiger 131 is a German Tiger I heavy tank captured in Tunisia by the British 48th Royal Tank Regiment during World War II
- USNS Mission Santa Barbara (T-AO-131) was a Mission Buenaventura-class fleet oiler during World War II
- USS Bandera (APA-131) was a is a United States Navy Haskell-class attack transport ship during World War II
- USS Buchanan (DD-131) was a United States Navy Wickes-class destroyer
- USS General T. H. Bliss (AP-131) was a United States Navy General G. O. Squier-class transport ship during World War II
- USS Hammann (DE-131) was a United States Navy Edsall-class destroyer escort during World War II
- USS Melucta (AK-131) was a United States Navy Crater-class cargo ship during World War II
- USS Walter X. Young (APD-131) was a ship of the United States Navy during World War II
- ZIL-131 is a 3.5-ton 6x6 army truck
In transportation
[edit]- London Buses route 131 is a Transport for London contracted bus route in London
- The Fiat 131 Mirafiori small/medium family car produced from 1974 to 1984
- STS-131 is a NASA Contingency Logistic Flight (CLF) of the Space Shuttle Atlantis which launched in April 2010
In other fields
[edit]131 is also:
- The year AD 131 or 131 BC
- 131 AH is a year in the Islamic calendar that corresponds to 748 – 749 CE.
- 131 Vala is an inner main belt asteroid
- Iodine-131, or radioiodine, is a radioisotope of iodine for medical and pharmaceutical use
- ACP-131 is the controlling publication for listing of Q codes and Z codes, as published by NATO Allied countries
- Sonnet 131 by William Shakespeare
- 131 is the medical emergency telephone number in Chile
- United States Citizenship and Immigration Services Form I-131 to apply for a travel document, reentry permit, refugee travel document or advance parole
- 131 is the ID3v1 tag equivalent to Indie music
See also
[edit]References
[edit]- ^ "Sloane's A005384 : Sophie Germain primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Sloane's A000928 : Irregular primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Ulam numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. 2016-04-18. Retrieved 2016-04-19.
- ^ Sloane, N. J. A. (ed.). "Sequence A046002 (Discriminants of imaginary quadratic fields with class number 5 (negated))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2024-08-03.
- ^ Sloane, N. J. A. (ed.). "Sequence A046005 (Discriminants of imaginary quadratic fields with class number 8 (negated).)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2024-08-03.