# ⓘ 127 (number)

## ⓘ 127 (number)

• It is the 7th Motzkin number.
• 127 is the smallest odd number that cant be written in the form p + 2 x for p=prime number and x=integer, since 127 - 2 0 = 126, 127 - 2 1 = 125, 127 - 2 = 123, 127 - 2 3 = 119, 127 - 2 4 = 111, 127 - 2 5 = 95, and 127 - 2 6 = 63 are all composite numbers.
• 127 is also a cuban prime of the form p = x 3 − y 3 / x − y {\displaystyle p=x^{3}-y^{3}/x-y}, x = y + 1 {\displaystyle x=y+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.
• It is the first nice Friedman number in base 10, since 127 = -1 + 2 7, as well as binary since 1111111 = 1 + 1 111 - 1 * 1.
• 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.
• 127 is the sum of the sums of the divisors of the first 12 positive integers.
• 127 is a centered hexagonal number.
• 127 is an isolated prime where neither p-2 nor p+2 are prime.
• As a Mersenne prime, 127 is related to the perfect number 8128. 127 is also an exponent for another Mersenne prime 2 127 - 1, which was discovered by Edouard 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 2 7 - 1, and 7 is equal to 2 3 - 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 a palindromic prime in nonary and binary.

## 1. In the military

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

## 2. 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

## 3. In other fields

127 is also:

• The year AD 127 or 127 BC
• The highest signed 8-bit integer, using twos complement
• 127 Hours is a film released in 2010
• 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
• Sonnet 127 by William Shakespeare
• The non-printable "Delete" DEL control character in ASCII.
• The atomic number of Unbiseptium, an element that has not yet been discovered
• 127 Johanna, a Main belt asteroid
• 127 AH is a year in the Islamic calendar that corresponds to 744 – 745 CE
• 127th Street Ensemble was a troupe of African-American actors which included Tupac Amaru Shakur
• The LZ 127 Graf Zeppelin, a dirigible
• 127 film, a film format