668133756 has 18 divisors (see below), whose sum is σ = 1688893752. Its totient is φ = 222711240.

The previous prime is 668133751. The next prime is 668133757. The reversal of 668133756 is 657331866.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668133751) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9279600 + ... + 9279671.

Almost surely, 2^668133756 is an apocalyptic number.

It is an amenable number.

668133756 is an abundant number, since it is smaller than the sum of its proper divisors (1020759996).

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

668133756 is a wasteful number, since it uses less digits than its factorization.

668133756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18559281 (or 18559276 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 668133756 is about 25848.2834246300. The cubic root of 668133756 is about 874.2208055380.

The spelling of 668133756 in words is "six hundred sixty-eight million, one hundred thirty-three thousand, seven hundred fifty-six".