640702825 has 48 divisors (see below), whose sum is σ = 943225344. Its totient is φ = 422611200.

The previous prime is 640702787. The next prime is 640702837. The reversal of 640702825 is 528207046.

It is not a de Polignac number, because 640702825 - 2⁹ = 640702313 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 501087 + ... + 502363.

It is an arithmetic number, because the mean of its divisors is an integer number (19650528).

Almost surely, 2^640702825 is an apocalyptic number.

It is an amenable number.

640702825 is a deficient number, since it is larger than the sum of its proper divisors (302522519).

640702825 is a wasteful number, since it uses less digits than its factorization.

640702825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1402 (or 1397 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 640702825 is about 25312.1082685738. The cubic root of 640702825 is about 862.0892169757.

The spelling of 640702825 in words is "six hundred forty million, seven hundred two thousand, eight hundred twenty-five".