257 is a prime number from 201-300. 257 has 2 factors, 1 and 257. It is the 55th prime number, and the ninth prime number from 201-300.
It is also the fourth Fermat number.
Proofs[]
As an Exponent of Mersenne Number[]
2257 - 1 is divisible by 535,006,138,814,359 and is therefore not a prime number.
Relationship with other odd numbers[]
The numbers before[]
- The previous prime number is 251.
- In particular, 253 is divisible by 11 and 23, and 255 is divisible by 3, 5, and 17.
- 251 and 257 are six numbers apart; therefore, they are sexy primes.
- The previous prime number before 251 is 241.
The numbers after[]
- The next prime number is 263.
- 259 is not a prime, because it is divisible by 7. 261 is divisible by 3.
- 257 and 263 are six numbers apart; therefore, they are sexy primes.
- 269 is the next prime number after 263.