640594128 has 40 divisors (see below), whose sum is σ = 1656367200. Its totient is φ = 213337984.

The previous prime is 640594121. The next prime is 640594151. The reversal of 640594128 is 821495046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640594121) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 53563 + ... + 64421.

It is an arithmetic number, because the mean of its divisors is an integer number (41409180).

Almost surely, 2^640594128 is an apocalyptic number.

It is an amenable number.

640594128 is an abundant number, since it is smaller than the sum of its proper divisors (1015773072).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640594128 is a wasteful number, since it uses less digits than its factorization.

640594128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12099 (or 12093 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 640594128 is about 25309.9610430360. The cubic root of 640594128 is about 862.0404622813.

The spelling of 640594128 in words is "six hundred forty million, five hundred ninety-four thousand, one hundred twenty-eight".