644004476236 has 24 divisors (see below), whose sum is σ = 1247813292096. Its totient is φ = 288360211920.

The previous prime is 644004476161. The next prime is 644004476249. The reversal of 644004476236 is 632674400446.

644004476236 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, 109224406 + ... + 109230301.

It is an arithmetic number, because the mean of its divisors is an integer number (51992220504).

Almost surely, 2^644004476236 is an apocalyptic number.

It is an amenable number.

644004476236 is a deficient number, since it is larger than the sum of its proper divisors (603808815860).

644004476236 is a wasteful number, since it uses less digits than its factorization.

644004476236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218454789 (or 218454787 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 46.

The spelling of 644004476236 in words is "six hundred forty-four billion, four million, four hundred seventy-six thousand, two hundred thirty-six".