640961536 has 22 divisors (see below), whose sum is σ = 1281299180. Its totient is φ = 320480256.

The previous prime is 640961521. The next prime is 640961593. The reversal of 640961536 is 635169046.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311946 + ... + 313993.

Almost surely, 2^640961536 is an apocalyptic number.

It is an amenable number.

640961536 is a deficient number, since it is larger than the sum of its proper divisors (640337644).

640961536 is an equidigital number, since it uses as much as digits as its factorization.

640961536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625959 (or 625941 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 640961536 is about 25317.2181726192. The cubic root of 640961536 is about 862.2052364166.

The spelling of 640961536 in words is "six hundred forty million, nine hundred sixty-one thousand, five hundred thirty-six".