644655112 has 32 divisors (see below), whose sum is σ = 1233555480. Its totient is φ = 315727360.

The previous prime is 644655101. The next prime is 644655131. The reversal of 644655112 is 211556446.

It can be written as a sum of positive squares in 4 ways, for example, as 644448996 + 206116 = 25386^2 + 454^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 449148 + ... + 450580.

Almost surely, 2^644655112 is an apocalyptic number.

It is an amenable number.

644655112 is a deficient number, since it is larger than the sum of its proper divisors (588900368).

644655112 is a wasteful number, since it uses less digits than its factorization.

644655112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2553 (or 2549 counting only the distinct ones).

The product of its digits is 28800, while the sum is 34.

The square root of 644655112 is about 25390.0593146215. The cubic root of 644655112 is about 863.8582336273.

The spelling of 644655112 in words is "six hundred forty-four million, six hundred fifty-five thousand, one hundred twelve".