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*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.<ref>{{Cite OEIS|A071148}}. Partial sums of sequence of odd primes; a(n) = sum of the first n odd primes.</ref> |
*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.<ref>{{Cite OEIS|A071148}}. Partial sums of sequence of odd primes; a(n) = sum of the first n odd primes.</ref> |
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*127 is the smallest odd number that can't be written in the form p + 2<sup>x</sup> for p=[[prime number]] and x=[[integer]], since 127 - 2<sup>0</sup> = 126, 127 - 2<sup>1</sup> = 125, 127 - 2<sup>2</sup> = 123, 127 - 2<sup>3</sup> = 119, 127 - 2<sup>4</sup> = 111, 127 - 2<sup>5</sup> = 95, and 127 - 2<sup>6</sup> = 63 are all [[composite number]]s.<ref>{{Cite OEIS|A006285|Odd numbers not of form p + 2^x (de Polignac numbers)}}</ref> |
*127 is the smallest odd number that can't be written in the form p + 2<sup>x</sup> for p=[[prime number]] and x=[[integer]], since 127 - 2<sup>0</sup> = 126, 127 - 2<sup>1</sup> = 125, 127 - 2<sup>2</sup> = 123, 127 - 2<sup>3</sup> = 119, 127 - 2<sup>4</sup> = 111, 127 - 2<sup>5</sup> = 95, and 127 - 2<sup>6</sup> = 63 are all [[composite number]]s.<ref>{{Cite OEIS|A006285|Odd numbers not of form p + 2^x (de Polignac numbers)}}</ref> |
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*127 is an isolated prime where |
*127 is an isolated prime where neither p-2 nor p+2 are prime. |
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==In the military== |
==In the military== |
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Revision as of 08:53, 11 March 2020
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|---|---|---|---|---|
| Cardinal | one hundred twenty-seven | |||
| Ordinal | 127th (one hundred twenty-seventh) | |||
| Factorization | prime | |||
| Prime | 31st | |||
| Divisors | 1, 127 | |||
| Greek numeral | ΡΚΖ´ | |||
| Roman numeral | CXXVII | |||
| Binary | 11111112 | |||
| Ternary | 112013 | |||
| Senary | 3316 | |||
| Octal | 1778 | |||
| Duodecimal | A712 | |||
| Hexadecimal | 7F16 | |||
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 - it 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.
- 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.
- It is the first nice Friedman number in base 10, since 127 = -1 + 27, as well as binary since 1111111 = (1 + 1)111 - 1 * 1.
- 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.
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 Template:Sclass-
- USS Alnitah (AK-127) was a United States Navy Template:Sclass- in World War II
- USS Raccoon (IX-127) was a United States Navy Template:Sclass-
- USS Tumult (AM-127) was a United States Navy Template:Sclass- for removing naval mines
In religion
- The biblical figure Sarah died at the age of 127.[8]
- According to the Book of Esther 1:1, the Persian Empire under Ahasuerus contained 127 provinces
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
- 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
- ^ "Sloane's A002407 : Cuban primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Sloane's A051634 : Strong primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Sloane's A003215 : Hex (or centered hexagonal) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ "Sloane's A001006 : Motzkin numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "Sara". Catholic Encyclopedia. Retrieved September 8, 2015.
- Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 136 - 138
