640912525 has 12 divisors (see below), whose sum is σ = 866980224. Its totient is φ = 466118000.

The previous prime is 640912501. The next prime is 640912537. The reversal of 640912525 is 525219046.

It is a happy number.

It is not a de Polignac number, because 640912525 - 2⁷ = 640912397 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1165021 + ... + 1165570.

It is an arithmetic number, because the mean of its divisors is an integer number (72248352).

Almost surely, 2^640912525 is an apocalyptic number.

It is an amenable number.

640912525 is a deficient number, since it is larger than the sum of its proper divisors (226067699).

640912525 is a wasteful number, since it uses less digits than its factorization.

640912525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2330612 (or 2330607 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 640912525 is about 25316.2502160174. The cubic root of 640912525 is about 862.1832597375.

The spelling of 640912525 in words is "six hundred forty million, nine hundred twelve thousand, five hundred twenty-five".