644477325 has 24 divisors (see below), whose sum is σ = 1068119136. Its totient is φ = 342888000.

The previous prime is 644477287. The next prime is 644477333. The reversal of 644477325 is 523774446.

It is not a de Polignac number, because 644477325 - 2¹⁴ = 644460941 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21370 + ... + 41780.

It is an arithmetic number, because the mean of its divisors is an integer number (44504964).

Almost surely, 2^644477325 is an apocalyptic number.

It is an amenable number.

644477325 is a deficient number, since it is larger than the sum of its proper divisors (423641811).

644477325 is a wasteful number, since it uses less digits than its factorization.

644477325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20845 (or 20840 counting only the distinct ones).

The product of its digits is 564480, while the sum is 42.

The square root of 644477325 is about 25386.5579588884. The cubic root of 644477325 is about 863.7788129253.

The spelling of 644477325 in words is "six hundred forty-four million, four hundred seventy-seven thousand, three hundred twenty-five".