644562564 has 24 divisors (see below), whose sum is σ = 1520880480. Its totient is φ = 212439744.

The previous prime is 644562547. The next prime is 644562617. The reversal of 644562564 is 465265446.

644562564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300694 + ... + 302829.

It is an arithmetic number, because the mean of its divisors is an integer number (63370020).

Almost surely, 2^644562564 is an apocalyptic number.

It is an amenable number.

644562564 is an abundant number, since it is smaller than the sum of its proper divisors (876317916).

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

644562564 is a wasteful number, since it uses less digits than its factorization.

644562564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603619 (or 603617 counting only the distinct ones).

The product of its digits is 691200, while the sum is 42.

The square root of 644562564 is about 25388.2367249086. The cubic root of 644562564 is about 863.8168925668.

The spelling of 644562564 in words is "six hundred forty-four million, five hundred sixty-two thousand, five hundred sixty-four".