644247953400 has 48 divisors (see below), whose sum is σ = 1997168657400. Its totient is φ = 171799454080.

The previous prime is 644247953387. The next prime is 644247953443. The reversal of 644247953400 is 4359742446.

It is a self number, because there is not a number n which added to its sum of digits gives 644247953400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 536872695 + ... + 536873894.

Almost surely, 2^644247953400 is an apocalyptic number.

644247953400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644247953400 is an abundant number, since it is smaller than the sum of its proper divisors (1352920704000).

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

644247953400 is a wasteful number, since it uses less digits than its factorization.

644247953400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073746608 (or 1073746599 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 48.

The spelling of 644247953400 in words is "six hundred forty-four billion, two hundred forty-seven million, nine hundred fifty-three thousand, four hundred".