644307080 has 16 divisors (see below), whose sum is σ = 1449691020. Its totient is φ = 257722816.

The previous prime is 644307047. The next prime is 644307091. The reversal of 644307080 is 80703446.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 644042884 + 264196 = 25378^2 + 514^2 .

It is a super-2 number, since 2×644307080² = 830263226676252800, which contains 22 as substring.

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, 8053799 + ... + 8053878.

Almost surely, 2^644307080 is an apocalyptic number.

It is an amenable number.

644307080 is an abundant number, since it is smaller than the sum of its proper divisors (805383940).

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

644307080 is a wasteful number, since it uses less digits than its factorization.

644307080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16107688 (or 16107684 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 644307080 is about 25383.2046834122. The cubic root of 644307080 is about 863.7027476816.

The spelling of 644307080 in words is "six hundred forty-four million, three hundred seven thousand, eighty".