644838315 has 32 divisors (see below), whose sum is σ = 1127402496. Its totient is φ = 312130560.

The previous prime is 644838301. The next prime is 644838323. The reversal of 644838315 is 513838446.

It is not a de Polignac number, because 644838315 - 2⁶ = 644838251 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108142 + ... + 113948.

It is an arithmetic number, because the mean of its divisors is an integer number (35231328).

Almost surely, 2^644838315 is an apocalyptic number.

644838315 is a deficient number, since it is larger than the sum of its proper divisors (482564181).

644838315 is a wasteful number, since it uses less digits than its factorization.

644838315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6499.

The product of its digits is 276480, while the sum is 42.

The square root of 644838315 is about 25393.6668285618. Note that the first 3 decimals coincide. The cubic root of 644838315 is about 863.9400584809.

The spelling of 644838315 in words is "six hundred forty-four million, eight hundred thirty-eight thousand, three hundred fifteen".