668456631 has 10 divisors (see below), whose sum is σ = 998558792. Its totient is φ = 445637700.

The previous prime is 668456623. The next prime is 668456647. The reversal of 668456631 is 136654866.

668456631 is a `hidden beast` number, since 6 + 6 + 8 + 4 + 5 + 6 + 631 = 666.

It is not a de Polignac number, because 668456631 - 2³ = 668456623 is a prime.

It is a super-2 number, since 2×668456631² = 893668535055740322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668456611) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4126195 + ... + 4126356.

Almost surely, 2^668456631 is an apocalyptic number.

668456631 is a deficient number, since it is larger than the sum of its proper divisors (330102161).

668456631 is an equidigital number, since it uses as much as digits as its factorization.

668456631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8252563 (or 8252554 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 668456631 is about 25854.5282494189. The cubic root of 668456631 is about 874.3616049834.

The spelling of 668456631 in words is "six hundred sixty-eight million, four hundred fifty-six thousand, six hundred thirty-one".