644746612 has 6 divisors (see below), whose sum is σ = 1128306578. Its totient is φ = 322373304.

The previous prime is 644746591. The next prime is 644746621. The reversal of 644746612 is 216647446.

644746612 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 475850596 + 168896016 = 21814^2 + 12996^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80593323 + ... + 80593330.

Almost surely, 2^644746612 is an apocalyptic number.

It is an amenable number.

644746612 is a deficient number, since it is larger than the sum of its proper divisors (483559966).

644746612 is a wasteful number, since it uses less digits than its factorization.

644746612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161186657 (or 161186655 counting only the distinct ones).

The product of its digits is 193536, while the sum is 40.

The square root of 644746612 is about 25391.8611369864. The cubic root of 644746612 is about 863.8991026582.

The spelling of 644746612 in words is "six hundred forty-four million, seven hundred forty-six thousand, six hundred twelve".