644893106 has 16 divisors (see below), whose sum is σ = 1136455488. Its totient is φ = 270584400.

The previous prime is 644893087. The next prime is 644893111. The reversal of 644893106 is 601398446.

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 7 ways as a sum of consecutive naturals, for example, 1127150 + ... + 1127721.

It is an arithmetic number, because the mean of its divisors is an integer number (71028468).

Almost surely, 2^644893106 is an apocalyptic number.

644893106 is a deficient number, since it is larger than the sum of its proper divisors (491562382).

644893106 is a wasteful number, since it uses less digits than its factorization.

644893106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2254897.

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 644893106 is about 25394.7456376314. The cubic root of 644893106 is about 863.9645270430.

The spelling of 644893106 in words is "six hundred forty-four million, eight hundred ninety-three thousand, one hundred six".