644536884 has 24 divisors (see below), whose sum is σ = 1514742880. Its totient is φ = 213299424.

The previous prime is 644536883. The next prime is 644536891. The reversal of 644536884 is 488635446.

644536884 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 not an unprimeable number, because it can be changed into a prime (644536883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191539 + ... + 194874.

Almost surely, 2^644536884 is an apocalyptic number.

It is an amenable number.

644536884 is an abundant number, since it is smaller than the sum of its proper divisors (870205996).

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

644536884 is a wasteful number, since it uses less digits than its factorization.

644536884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386559 (or 386557 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 48.

The square root of 644536884 is about 25387.7309738385. The cubic root of 644536884 is about 863.8054206458.

The spelling of 644536884 in words is "six hundred forty-four million, five hundred thirty-six thousand, eight hundred eighty-four".