644311325 has 24 divisors (see below), whose sum is σ = 915560448. Its totient is φ = 440614080.

The previous prime is 644311319. The next prime is 644311379. The reversal of 644311325 is 523113446.

It is not a de Polignac number, because 644311325 - 2⁴ = 644311309 is a prime.

It is a Duffinian number.

It is a Curzon number.

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, 62219 + ... + 71831.

It is an arithmetic number, because the mean of its divisors is an integer number (38148352).

Almost surely, 2^644311325 is an apocalyptic number.

It is an amenable number.

644311325 is a deficient number, since it is larger than the sum of its proper divisors (271249123).

644311325 is a wasteful number, since it uses less digits than its factorization.

644311325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10013 (or 10008 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 644311325 is about 25383.2883015578. The cubic root of 644311325 is about 863.7046445049.

It can be divided in two parts, 64431 and 1325, that added together give a palindrome (65756).

The spelling of 644311325 in words is "six hundred forty-four million, three hundred eleven thousand, three hundred twenty-five".