666655904 has 12 divisors (see below), whose sum is σ = 1312478874. Its totient is φ = 333327936.

The previous prime is 666655879. The next prime is 666655909. The reversal of 666655904 is 409556666.

It is a happy number.

666655904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 358723600 + 307932304 = 18940^2 + 17548^2 .

It is not an unprimeable number, because it can be changed into a prime (666655909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10416467 + ... + 10416530.

Almost surely, 2^666655904 is an apocalyptic number.

It is an amenable number.

666655904 is a deficient number, since it is larger than the sum of its proper divisors (645822970).

666655904 is a wasteful number, since it uses less digits than its factorization.

666655904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20833007 (or 20832999 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 47.

The square root of 666655904 is about 25819.6805557311. The cubic root of 666655904 is about 873.5757636833.

The spelling of 666655904 in words is "six hundred sixty-six million, six hundred fifty-five thousand, nine hundred four".