644673025 has 12 divisors (see below), whose sum is σ = 800705200. Its totient is φ = 514892880.

The previous prime is 644673019. The next prime is 644673041. The reversal of 644673025 is 520376446.

It is not a de Polignac number, because 644673025 - 2²³ = 636284417 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5355 + ... + 36304.

Almost surely, 2^644673025 is an apocalyptic number.

It is an amenable number.

644673025 is a deficient number, since it is larger than the sum of its proper divisors (156032175).

644673025 is a wasteful number, since it uses less digits than its factorization.

644673025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42288 (or 42283 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 644673025 is about 25390.4120683379. The cubic root of 644673025 is about 863.8662348820.

The spelling of 644673025 in words is "six hundred forty-four million, six hundred seventy-three thousand, twenty-five".