664445979 has 24 divisors (see below), whose sum is σ = 1012007360. Its totient is φ = 418928112.

The previous prime is 664445939. The next prime is 664445983. The reversal of 664445979 is 979544466.

It is a happy number.

664445979 is a `hidden beast` number, since 6 + 6 + 4 + 44 + 597 + 9 = 666.

664445979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 664445979 - 2⁷ = 664445851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664445939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106932 + ... + 112974.

Almost surely, 2^664445979 is an apocalyptic number.

664445979 is a deficient number, since it is larger than the sum of its proper divisors (347561381).

664445979 is a wasteful number, since it uses less digits than its factorization.

664445979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6711 (or 6708 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 54.

The square root of 664445979 is about 25776.8496717500. The cubic root of 664445979 is about 872.6094110514.

The spelling of 664445979 in words is "six hundred sixty-four million, four hundred forty-five thousand, nine hundred seventy-nine".