644052225 has 24 divisors (see below), whose sum is σ = 1127472480. Its totient is φ = 323288320.

The previous prime is 644052217. The next prime is 644052239. The reversal of 644052225 is 522250446.

It is a happy number.

It is not a de Polignac number, because 644052225 - 2³ = 644052217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644052192 and 644052201.

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 23 ways as a sum of consecutive naturals, for example, 251295 + ... + 253844.

It is an arithmetic number, because the mean of its divisors is an integer number (46978020).

Almost surely, 2^644052225 is an apocalyptic number.

It is an amenable number.

644052225 is a deficient number, since it is larger than the sum of its proper divisors (483420255).

644052225 is a wasteful number, since it uses less digits than its factorization.

644052225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505169 (or 505164 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The square root of 644052225 is about 25378.1840366879. The cubic root of 644052225 is about 863.5888537535.

The spelling of 644052225 in words is "six hundred forty-four million, fifty-two thousand, two hundred twenty-five".