644382080 has 32 divisors (see below), whose sum is σ = 1540477440. Its totient is φ = 257752576.

The previous prime is 644382071. The next prime is 644382091. The reversal of 644382080 is 80283446.

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 644382080.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 502784 + ... + 504063.

It is an arithmetic number, because the mean of its divisors is an integer number (48139920).

Almost surely, 2^644382080 is an apocalyptic number.

It is an amenable number.

644382080 is an abundant number, since it is smaller than the sum of its proper divisors (896095360).

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

644382080 is a wasteful number, since it uses less digits than its factorization.

644382080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006866 (or 1006854 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 35.

The square root of 644382080 is about 25384.6819952506. The cubic root of 644382080 is about 863.7362592347.

The spelling of 644382080 in words is "six hundred forty-four million, three hundred eighty-two thousand, eighty".