640100625 has 40 divisors (see below), whose sum is σ = 1070207424. Its totient is φ = 340200000.

The previous prime is 640100621. The next prime is 640100639. The reversal of 640100625 is 526001046.

It is not a de Polignac number, because 640100625 - 2² = 640100621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640100595 and 640100604.

It is not an unprimeable number, because it can be changed into a prime (640100621) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 912775 + ... + 913475.

Almost surely, 2^640100625 is an apocalyptic number.

It is an amenable number.

640100625 is a deficient number, since it is larger than the sum of its proper divisors (430106799).

640100625 is an equidigital number, since it uses as much as digits as its factorization.

640100625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1211 (or 1196 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 640100625 is about 25300.2099793658. The cubic root of 640100625 is about 861.8190382273.

The spelling of 640100625 in words is "six hundred forty million, one hundred thousand, six hundred twenty-five".