664642660 has 48 divisors (see below), whose sum is σ = 1524841920. Its totient is φ = 241338240.

The previous prime is 664642637. The next prime is 664642691. The reversal of 664642660 is 66246466.

664642660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 187222 + ... + 190738.

It is an arithmetic number, because the mean of its divisors is an integer number (31767540).

Almost surely, 2^664642660 is an apocalyptic number.

It is an amenable number.

664642660 is an abundant number, since it is smaller than the sum of its proper divisors (860199260).

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

664642660 is a wasteful number, since it uses less digits than its factorization.

664642660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4396 (or 4394 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 40.

The square root of 664642660 is about 25780.6644600173. The cubic root of 664642660 is about 872.6955022039.

The spelling of 664642660 in words is "six hundred sixty-four million, six hundred forty-two thousand, six hundred sixty".