640555875 has 48 divisors (see below), whose sum is σ = 1158231360. Its totient is φ = 340588800.

The previous prime is 640555871. The next prime is 640555889. The reversal of 640555875 is 578555046.

640555875 is a `hidden beast` number, since 64 + 0 + 5 + 5 + 587 + 5 = 666.

640555875 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 640555875 - 2² = 640555871 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 640555875.

It is not an unprimeable number, because it can be changed into a prime (640555871) 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, 493227 + ... + 494523.

It is an arithmetic number, because the mean of its divisors is an integer number (24129820).

Almost surely, 2^640555875 is an apocalyptic number.

640555875 is a deficient number, since it is larger than the sum of its proper divisors (517675485).

640555875 is a wasteful number, since it uses less digits than its factorization.

640555875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757 (or 1744 counting only the distinct ones).

The product of its (nonzero) digits is 840000, while the sum is 45.

The square root of 640555875 is about 25309.2053411402. The cubic root of 640555875 is about 862.0233030595.

The spelling of 640555875 in words is "six hundred forty million, five hundred fifty-five thousand, eight hundred seventy-five".