644050064 has 40 divisors (see below), whose sum is σ = 1453032000. Its totient is φ = 270811008.

The previous prime is 644050063. The next prime is 644050073. The reversal of 644050064 is 460050446.

It is not an unprimeable number, because it can be changed into a prime (644050061) by changing a digit.

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, 48314 + ... + 60185.

It is an arithmetic number, because the mean of its divisors is an integer number (36325800).

Almost surely, 2^644050064 is an apocalyptic number.

It is an amenable number.

644050064 is an abundant number, since it is smaller than the sum of its proper divisors (808981936).

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

644050064 is a wasteful number, since it uses less digits than its factorization.

644050064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108567 (or 108561 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 644050064 is about 25378.1414607138. The cubic root of 644050064 is about 863.5878878806.

The spelling of 644050064 in words is "six hundred forty-four million, fifty thousand, sixty-four".