644315697 has 24 divisors (see below), whose sum is σ = 955674720. Its totient is φ = 418057920.

The previous prime is 644315671. The next prime is 644315701. The reversal of 644315697 is 796513446.

It is not a de Polignac number, because 644315697 - 2¹⁰ = 644314673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644316697) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 170454 + ... + 174192.

It is an arithmetic number, because the mean of its divisors is an integer number (39819780).

Almost surely, 2^644315697 is an apocalyptic number.

It is an amenable number.

644315697 is a deficient number, since it is larger than the sum of its proper divisors (311359023).

644315697 is a wasteful number, since it uses less digits than its factorization.

644315697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4253 (or 4250 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 644315697 is about 25383.3744210655. The cubic root of 644315697 is about 863.7065980678.

The spelling of 644315697 in words is "six hundred forty-four million, three hundred fifteen thousand, six hundred ninety-seven".