640918252 has 24 divisors (see below), whose sum is σ = 1212368192. Its totient is φ = 294710400.

The previous prime is 640918247. The next prime is 640918261. The reversal of 640918252 is 252819046.

640918252 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 7 ways as a sum of consecutive naturals, for example, 8649 + ... + 36832.

Almost surely, 2^640918252 is an apocalyptic number.

It is an amenable number.

640918252 is a deficient number, since it is larger than the sum of its proper divisors (571449940).

640918252 is a wasteful number, since it uses less digits than its factorization.

640918252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45769 (or 45767 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 640918252 is about 25316.3633249327. The cubic root of 640918252 is about 862.1858277993.

The spelling of 640918252 in words is "six hundred forty million, nine hundred eighteen thousand, two hundred fifty-two".