644060764 has 12 divisors (see below), whose sum is σ = 1127345184. Its totient is φ = 321962144.

The previous prime is 644060731. The next prime is 644060783. The reversal of 644060764 is 467060446.

644060764 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 3 ways as a sum of consecutive naturals, for example, 8397 + ... + 36859.

It is an arithmetic number, because the mean of its divisors is an integer number (93945432).

Almost surely, 2^644060764 is an apocalyptic number.

It is an amenable number.

644060764 is a deficient number, since it is larger than the sum of its proper divisors (483284420).

644060764 is a wasteful number, since it uses less digits than its factorization.

644060764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34124 (or 34122 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 37.

The square root of 644060764 is about 25378.3522711779. The cubic root of 644060764 is about 863.5926702931.

The spelling of 644060764 in words is "six hundred forty-four million, sixty thousand, seven hundred sixty-four".