312997691 has 2 divisors, whose sum is σ = 312997692. Its totient is φ = 312997690.

The previous prime is 312997681. The next prime is 312997709. The reversal of 312997691 is 196799213.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312997691 is a prime.

It is not a weakly prime, because it can be changed into another prime (312997631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156498845 + 156498846.

It is an arithmetic number, because the mean of its divisors is an integer number (156498846).

Almost surely, 2^312997691 is an apocalyptic number.

312997691 is a deficient number, since it is larger than the sum of its proper divisors (1).

312997691 is an equidigital number, since it uses as much as digits as its factorization.

312997691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 47.

The square root of 312997691 is about 17691.7407566356. The cubic root of 312997691 is about 678.9644640626.

The spelling of 312997691 in words is "three hundred twelve million, nine hundred ninety-seven thousand, six hundred ninety-one".