127 is a prime number from 101-200. 127 has 2 factors, 1 and 127. It is the 31st prime number, and the sixth prime number from 101-200. It is the largest signed 8-bit integer using two's complement.
Proofs[]
Therefore, 127 is a prime number.
As an Exponent of Mersenne Number[]
2127 - 1 is a prime number as well as the 12th Mersenne prime. Its decimal expansion is 170,141,183,460,469,231,731,687,303,715,884,105,727.
Relationship with other odd numbers[]
The numbers before[]
- 113 is the previous prime number.
- The distance between 127 and 113 is 14. This is the largest gap between two consecutive prime numbers between 1 and 200.
- The prime factorization of 115 is 5 × 23.
- The prime factorization of 117 is 32 × 13.
- The prime factorization of 119 is 7 × 17.
- 121 is a square number, equal to 112.
- The prime factorization of 123 is 3 × 41.
The numbers after[]
- 129 is a composite number; its prime factorization is 3 × 43.
- 131 is the prime number following 127.
- The difference between 131 and 127 is 4. Therefore, they are cousin primes.
- 133 is a composite number; its prime factorization is 7 × 19.
- 135 is a composite number; its prime factorization is 33 × 5.
- 137 is the prime number following 131.
Trivia[]
- 127 is the first Friedman prime, since 127 = 27 - 1. It is also the first nice Friedman prime, since 127 = -1 + 27.
- 2127 - 1 was proven to be prime in 1876 and held the record for the largest known prime number for 75 years.
- There are 127 prime numbers between 2,000 and 3,000.
- Since 129 = 127 + 2 is a semiprime, 127 is a Chen prime.
- 127 is the smallest prime number that can be expressed as the sum of two or more odd primes.
- 127 is an isolated prime, since 127 - 2 and 127 + 2 are not prime.
- 127 is the largest number with the property of being equal to 1 × prime(1) + 2 × prime(2) + 7 × prime(7), where prime(n) is the nth prime number. The only other number with this property is 43.
- 127 is the 31st prime number, meaning it is the smallest Mersenne prime with a Mersenne prime index, since 31 is a Mersenne prime. Furthermore, 127 is a super-prime, since 31 is also prime.
- 127 is the smallest prime number that the element with the atomic number is part of the extended periodic table.