644486512 has 10 divisors (see below), whose sum is σ = 1248692648. Its totient is φ = 322243248.

The previous prime is 644486489. The next prime is 644486543. The reversal of 644486512 is 215684446.

It is a super-2 number, since 2×644486512² = 830725728299852288, which contains 22 as substring.

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 as a sum of consecutive naturals, namely, 20140188 + ... + 20140219.

Almost surely, 2^644486512 is an apocalyptic number.

It is an amenable number.

644486512 is a deficient number, since it is larger than the sum of its proper divisors (604206136).

644486512 is a wasteful number, since it uses less digits than its factorization.

644486512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40280415 (or 40280409 counting only the distinct ones).

The product of its digits is 184320, while the sum is 40.

The square root of 644486512 is about 25386.7389004575. The cubic root of 644486512 is about 863.7829172840.

The spelling of 644486512 in words is "six hundred forty-four million, four hundred eighty-six thousand, five hundred twelve".