668904172 has 12 divisors (see below), whose sum is σ = 1173594240. Its totient is φ = 333591536.

The previous prime is 668904163. The next prime is 668904211. The reversal of 668904172 is 271409866.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213388 + ... + 216499.

It is an arithmetic number, because the mean of its divisors is an integer number (97799520).

Almost surely, 2^668904172 is an apocalyptic number.

It is an amenable number.

668904172 is a deficient number, since it is larger than the sum of its proper divisors (504690068).

668904172 is a wasteful number, since it uses less digits than its factorization.

668904172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430280 (or 430278 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 668904172 is about 25863.1817841502. The cubic root of 668904172 is about 874.5566938650.

The spelling of 668904172 in words is "six hundred sixty-eight million, nine hundred four thousand, one hundred seventy-two".