312997681 has 2 divisors, whose sum is σ = 312997682. Its totient is φ = 312997680.

The previous prime is 312997679. The next prime is 312997691. The reversal of 312997681 is 186799213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 276889600 + 36108081 = 16640^2 + 6009^2 .

It is a cyclic number.

It is not a de Polignac number, because 312997681 - 2¹ = 312997679 is a prime.

It is a super-2 number, since 2×312997681² = 195935096622755522, which contains 22 as substring.

Together with 312997679, it forms a pair of twin primes.

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 (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156498840 + 156498841.

It is an arithmetic number, because the mean of its divisors is an integer number (156498841).

Almost surely, 2^312997681 is an apocalyptic number.

It is an amenable number.

312997681 is a deficient number, since it is larger than the sum of its proper divisors (1).

312997681 is an equidigital number, since it uses as much as digits as its factorization.

312997681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 46.

The square root of 312997681 is about 17691.7404740178. The cubic root of 312997681 is about 678.9644568319.

The spelling of 312997681 in words is "three hundred twelve million, nine hundred ninety-seven thousand, six hundred eighty-one".