640521425165 has 32 divisors (see below), whose sum is σ = 775480559616. Its totient is φ = 507871203840.

The previous prime is 640521425111. The next prime is 640521425179. The reversal of 640521425165 is 561524125046.

It is a de Polignac number, because none of the positive numbers 2^k-640521425165 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 31 ways as a sum of consecutive naturals, for example, 431908514 + ... + 431909996.

It is an arithmetic number, because the mean of its divisors is an integer number (24233767488).

Almost surely, 2^640521425165 is an apocalyptic number.

It is an amenable number.

640521425165 is a deficient number, since it is larger than the sum of its proper divisors (134959134451).

640521425165 is a wasteful number, since it uses less digits than its factorization.

640521425165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3029.

The product of its (nonzero) digits is 288000, while the sum is 41.

The spelling of 640521425165 in words is "six hundred forty billion, five hundred twenty-one million, four hundred twenty-five thousand, one hundred sixty-five".