317991761 has 2 divisors, whose sum is σ = 317991762. Its totient is φ = 317991760.

The previous prime is 317991743. The next prime is 317991763. The reversal of 317991761 is 167199713.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 274101136 + 43890625 = 16556^2 + 6625^2 .

It is an emirp because it is prime and its reverse (167199713) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 317991761 - 2⁶ = 317991697 is a prime.

It is a super-2 number, since 2×317991761² = 202237520127762242, which contains 22 as substring.

Together with 317991763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (317991763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158995880 + 158995881.

It is an arithmetic number, because the mean of its divisors is an integer number (158995881).

Almost surely, 2^317991761 is an apocalyptic number.

It is an amenable number.

317991761 is a deficient number, since it is larger than the sum of its proper divisors (1).

317991761 is an equidigital number, since it uses as much as digits as its factorization.

317991761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 44.

The square root of 317991761 is about 17832.3234885418. The cubic root of 317991761 is about 682.5565248126.

The spelling of 317991761 in words is "three hundred seventeen million, nine hundred ninety-one thousand, seven hundred sixty-one".