644441612 has 6 divisors (see below), whose sum is σ = 1127772828. Its totient is φ = 322220804.

The previous prime is 644441579. The next prime is 644441621. The reversal of 644441612 is 216144446.

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, 80555198 + ... + 80555205.

It is an arithmetic number, because the mean of its divisors is an integer number (187962138).

Almost surely, 2^644441612 is an apocalyptic number.

It is an amenable number.

644441612 is a deficient number, since it is larger than the sum of its proper divisors (483331216).

644441612 is a wasteful number, since it uses less digits than its factorization.

644441612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161110407 (or 161110405 counting only the distinct ones).

The product of its digits is 18432, while the sum is 32.

The square root of 644441612 is about 25385.8545650920. The cubic root of 644441612 is about 863.7628575139.

The spelling of 644441612 in words is "six hundred forty-four million, four hundred forty-one thousand, six hundred twelve".