317720657 has 2 divisors, whose sum is σ = 317720658. Its totient is φ = 317720656.

The previous prime is 317720651. The next prime is 317720659. The reversal of 317720657 is 756027713.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 313431616 + 4289041 = 17704^2 + 2071^2 .

It is a cyclic number.

It is not a de Polignac number, because 317720657 - 2⁸ = 317720401 is a prime.

It is a super-3 number, since 3×317720657³ (a number of 26 digits) contains 333 as substring.

Together with 317720659, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 317720657.

It is not a weakly prime, because it can be changed into another prime (317720651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158860328 + 158860329.

It is an arithmetic number, because the mean of its divisors is an integer number (158860329).

Almost surely, 2^317720657 is an apocalyptic number.

It is an amenable number.

317720657 is a deficient number, since it is larger than the sum of its proper divisors (1).

317720657 is an equidigital number, since it uses as much as digits as its factorization.

317720657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61740, while the sum is 38.

The square root of 317720657 is about 17824.7203905138. The cubic root of 317720657 is about 682.3624983858.

The spelling of 317720657 in words is "three hundred seventeen million, seven hundred twenty thousand, six hundred fifty-seven".