644334563160 has 128 divisors (see below), whose sum is σ = 2153937240000. Its totient is φ = 171330121728.

The previous prime is 644334563153. The next prime is 644334563209. The reversal of 644334563160 is 61365433446.

644334563160 is a `hidden beast` number, since 6 + 4 + 4 + 3 + 3 + 4 + 5 + 631 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 477817 + ... + 1231656.

Almost surely, 2^644334563160 is an apocalyptic number.

644334563160 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644334563160 is an abundant number, since it is smaller than the sum of its proper divisors (1509602676840).

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

644334563160 is a wasteful number, since it uses less digits than its factorization.

644334563160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1709842 (or 1709832 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 45.

The spelling of 644334563160 in words is "six hundred forty-four billion, three hundred thirty-four million, five hundred sixty-three thousand, one hundred sixty".