660686672 has 20 divisors (see below), whose sum is σ = 1280790420. Its totient is φ = 330160128.

The previous prime is 660686651. The next prime is 660686681. The reversal of 660686672 is 276686066.

It can be written as a sum of positive squares in 2 ways, for example, as 247621696 + 413064976 = 15736^2 + 20324^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21104 + ... + 42032.

It is an arithmetic number, because the mean of its divisors is an integer number (64039521).

Almost surely, 2^660686672 is an apocalyptic number.

It is an amenable number.

660686672 is a deficient number, since it is larger than the sum of its proper divisors (620103748).

660686672 is a wasteful number, since it uses less digits than its factorization.

660686672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22910 (or 22904 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 47.

The square root of 660686672 is about 25703.8260187078. The cubic root of 660686672 is about 870.9606124400.

The spelling of 660686672 in words is "six hundred sixty million, six hundred eighty-six thousand, six hundred seventy-two".