644080320788 has 48 divisors (see below), whose sum is σ = 1197026557440. Its totient is φ = 302383692000.

The previous prime is 644080320743. The next prime is 644080320823. The reversal of 644080320788 is 887023080446.

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 15 ways as a sum of consecutive naturals, for example, 5020523 + ... + 5147213.

It is an arithmetic number, because the mean of its divisors is an integer number (24938053280).

Almost surely, 2^644080320788 is an apocalyptic number.

It is an amenable number.

644080320788 is a deficient number, since it is larger than the sum of its proper divisors (552946236652).

644080320788 is a wasteful number, since it uses less digits than its factorization.

644080320788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127308 (or 127306 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 50.

The spelling of 644080320788 in words is "six hundred forty-four billion, eighty million, three hundred twenty thousand, seven hundred eighty-eight".