640807525 has 12 divisors (see below), whose sum is σ = 796449892. Its totient is φ = 511453440.

The previous prime is 640807487. The next prime is 640807549. The reversal of 640807525 is 525708046.

It is a happy number.

640807525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 107474689 + 533332836 = 10367^2 + 23094^2 .

It is not a de Polignac number, because 640807525 - 2¹⁷ = 640676453 is a prime.

It is a Duffinian number.

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, 18774 + ... + 40423.

Almost surely, 2^640807525 is an apocalyptic number.

It is an amenable number.

640807525 is a deficient number, since it is larger than the sum of its proper divisors (155642367).

640807525 is a wasteful number, since it uses less digits than its factorization.

640807525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59640 (or 59635 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 37.

The square root of 640807525 is about 25314.1763642430. The cubic root of 640807525 is about 862.1361736517.

The spelling of 640807525 in words is "six hundred forty million, eight hundred seven thousand, five hundred twenty-five".