640437874644 has 48 divisors (see below), whose sum is σ = 1505492267328. Its totient is φ = 211888735488.

The previous prime is 640437874627. The next prime is 640437874651. The reversal of 640437874644 is 446478734046.

640437874644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12315562 + ... + 12367454.

It is an arithmetic number, because the mean of its divisors is an integer number (31364422236).

Almost surely, 2^640437874644 is an apocalyptic number.

It is an amenable number.

640437874644 is an abundant number, since it is smaller than the sum of its proper divisors (865054392684).

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

640437874644 is a wasteful number, since it uses less digits than its factorization.

640437874644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59544 (or 59542 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 57.

The spelling of 640437874644 in words is "six hundred forty billion, four hundred thirty-seven million, eight hundred seventy-four thousand, six hundred forty-four".