640993375 has 32 divisors (see below), whose sum is σ = 876432960. Its totient is φ = 464176000.

The previous prime is 640993277. The next prime is 640993391. The reversal of 640993375 is 573399046.

640993375 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 640993375 - 2⁷ = 640993247 is a prime.

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, 369009 + ... + 370741.

It is an arithmetic number, because the mean of its divisors is an integer number (27388530).

Almost surely, 2^640993375 is an apocalyptic number.

640993375 is a deficient number, since it is larger than the sum of its proper divisors (235439585).

640993375 is a wasteful number, since it uses less digits than its factorization.

640993375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028 (or 2018 counting only the distinct ones).

The product of its (nonzero) digits is 612360, while the sum is 46.

The square root of 640993375 is about 25317.8469661225. The cubic root of 640993375 is about 862.2195125193.

The spelling of 640993375 in words is "six hundred forty million, nine hundred ninety-three thousand, three hundred seventy-five".