656478631 has 2 divisors, whose sum is σ = 656478632. Its totient is φ = 656478630.

The previous prime is 656478619. The next prime is 656478649. The reversal of 656478631 is 136874656.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 656478631 - 2²⁷ = 522260903 is a prime.

It is a super-2 number, since 2×656478631² = 861928385919268322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656478611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328239315 + 328239316.

It is an arithmetic number, because the mean of its divisors is an integer number (328239316).

Almost surely, 2^656478631 is an apocalyptic number.

656478631 is a deficient number, since it is larger than the sum of its proper divisors (1).

656478631 is an equidigital number, since it uses as much as digits as its factorization.

656478631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 46.

The square root of 656478631 is about 25621.8389464925. The cubic root of 656478631 is about 869.1075672755.

The spelling of 656478631 in words is "six hundred fifty-six million, four hundred seventy-eight thousand, six hundred thirty-one".