668556956 has 24 divisors (see below), whose sum is σ = 1181300736. Its totient is φ = 331052400.

The previous prime is 668556953. The next prime is 668556961. The reversal of 668556956 is 659655866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668556953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460031 + ... + 461481.

It is an arithmetic number, because the mean of its divisors is an integer number (49220864).

Almost surely, 2^668556956 is an apocalyptic number.

It is an amenable number.

668556956 is a deficient number, since it is larger than the sum of its proper divisors (512743780).

668556956 is a wasteful number, since it uses less digits than its factorization.

668556956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2489 (or 2487 counting only the distinct ones).

The product of its digits is 11664000, while the sum is 56.

The square root of 668556956 is about 25856.4683590006. The cubic root of 668556956 is about 874.4053455123.

The spelling of 668556956 in words is "six hundred sixty-eight million, five hundred fifty-six thousand, nine hundred fifty-six".