668715904 has 32 divisors (see below), whose sum is σ = 1364711040. Its totient is φ = 326200320.

The previous prime is 668715889. The next prime is 668715907. The reversal of 668715904 is 409517866.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668715907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58464 + ... + 68959.

It is an arithmetic number, because the mean of its divisors is an integer number (42647220).

Almost surely, 2^668715904 is an apocalyptic number.

668715904 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

668715904 is an abundant number, since it is smaller than the sum of its proper divisors (695995136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668715904 is a wasteful number, since it uses less digits than its factorization.

668715904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127478 (or 127466 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 668715904 is about 25859.5418366219. The cubic root of 668715904 is about 874.4746360276.

The spelling of 668715904 in words is "six hundred sixty-eight million, seven hundred fifteen thousand, nine hundred four".