644288160 has 48 divisors (see below), whose sum is σ = 2029509216. Its totient is φ = 171810048.

The previous prime is 644288149. The next prime is 644288179. The reversal of 644288160 is 61882446.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 670654 + ... + 671613.

It is an arithmetic number, because the mean of its divisors is an integer number (42281442).

Almost surely, 2^644288160 is an apocalyptic number.

644288160 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644288160 is an abundant number, since it is smaller than the sum of its proper divisors (1385221056).

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

644288160 is a wasteful number, since it uses less digits than its factorization.

644288160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342285 (or 1342277 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 39.

The square root of 644288160 is about 25382.8319932981. The cubic root of 644288160 is about 863.6942934230.

It can be divided in two parts, 6 and 44288160, that added together give a triangular number (44288166 = T₉₄₁₁).

The spelling of 644288160 in words is "six hundred forty-four million, two hundred eighty-eight thousand, one hundred sixty".