640635225 has 48 divisors (see below), whose sum is σ = 1137016512. Its totient is φ = 317122560.

The previous prime is 640635211. The next prime is 640635227. The reversal of 640635225 is 522536046.

640635225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640635225 - 2⁶ = 640635161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640635227) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 89634 + ... + 96516.

It is an arithmetic number, because the mean of its divisors is an integer number (23687844).

Almost surely, 2^640635225 is an apocalyptic number.

It is an amenable number.

640635225 is a deficient number, since it is larger than the sum of its proper divisors (496381287).

640635225 is a wasteful number, since it uses less digits than its factorization.

640635225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6986 (or 6981 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 33.

The square root of 640635225 is about 25310.7729040423. The cubic root of 640635225 is about 862.0588964806.

The spelling of 640635225 in words is "six hundred forty million, six hundred thirty-five thousand, two hundred twenty-five".