647 is a prime number from 601-700. 647 has 2 factors, 1 and 647. It is the 118th prime number, and the ninth prime number from 601-700.

Proofs[]
Relationship with other odd numbers[]
The numbers before[]
- The previous prime number is 643.
- 643 and 647 are four numbers apart; therefore, they are cousin primes.
- The previous prime number before 643 is 641.
- 641 and 647 are six numbers apart; therefore, they are sexy primes.
The numbers after[]
- The next prime number is 653.
- 647 and 653 are six numbers apart; therefore, they are sexy primes.
- 649 is divisible by 11, therefore not a prime number.
- 659 is the next prime number after 653.