397689631 has 2 divisors, whose sum is σ = 397689632. Its totient is φ = 397689630.

The previous prime is 397689587. The next prime is 397689637. The reversal of 397689631 is 136986793.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397689631 is a prime.

It is a super-2 number, since 2×397689631² = 316314085209832322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397689637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198844815 + 198844816.

It is an arithmetic number, because the mean of its divisors is an integer number (198844816).

Almost surely, 2^397689631 is an apocalyptic number.

397689631 is a deficient number, since it is larger than the sum of its proper divisors (1).

397689631 is an equidigital number, since it uses as much as digits as its factorization.

397689631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1469664, while the sum is 52.

The square root of 397689631 is about 19942.1571300599. The cubic root of 397689631 is about 735.3849810351.

The spelling of 397689631 in words is "three hundred ninety-seven million, six hundred eighty-nine thousand, six hundred thirty-one".