668972977820 has 24 divisors (see below), whose sum is σ = 1605535147104. Its totient is φ = 229362163776.

The previous prime is 668972977819. The next prime is 668972977847. The reversal of 668972977820 is 28779279866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2389189067 + ... + 2389189346.

It is an arithmetic number, because the mean of its divisors is an integer number (66897297796).

Almost surely, 2^668972977820 is an apocalyptic number.

It is an amenable number.

668972977820 is an abundant number, since it is smaller than the sum of its proper divisors (936562169284).

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

668972977820 is a wasteful number, since it uses less digits than its factorization.

668972977820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4778378429 (or 4778378427 counting only the distinct ones).

The product of its (nonzero) digits is 256048128, while the sum is 71.

The spelling of 668972977820 in words is "six hundred sixty-eight billion, nine hundred seventy-two million, nine hundred seventy-seven thousand, eight hundred twenty".