668922721316 has 12 divisors (see below), whose sum is σ = 1202252999388. Its totient is φ = 325421864352.

The previous prime is 668922721231. The next prime is 668922721321. The reversal of 668922721316 is 613127229866.

It can be written as a sum of positive squares in 2 ways, for example, as 545967298816 + 122955422500 = 738896^2 + 350650^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2259873911 + ... + 2259874206.

It is an arithmetic number, because the mean of its divisors is an integer number (100187749949).

Almost surely, 2^668922721316 is an apocalyptic number.

It is an amenable number.

668922721316 is a deficient number, since it is larger than the sum of its proper divisors (533330278072).

668922721316 is a wasteful number, since it uses less digits than its factorization.

668922721316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4519748158 (or 4519748156 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 53.

The spelling of 668922721316 in words is "six hundred sixty-eight billion, nine hundred twenty-two million, seven hundred twenty-one thousand, three hundred sixteen".