644334363 has 12 divisors (see below), whose sum is σ = 933740808. Its totient is φ = 428155200.

The previous prime is 644334359. The next prime is 644334367. The reversal of 644334363 is 363433446.

644334363 is a `hidden beast` number, since 644 + 3 + 3 + 4 + 3 + 6 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (644334359) and next prime (644334367).

It is not a de Polignac number, because 644334363 - 2² = 644334359 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644334367) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113838 + ... + 119363.

It is an arithmetic number, because the mean of its divisors is an integer number (77811734).

Almost surely, 2^644334363 is an apocalyptic number.

644334363 is a deficient number, since it is larger than the sum of its proper divisors (289406445).

644334363 is a wasteful number, since it uses less digits than its factorization.

644334363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233514 (or 233511 counting only the distinct ones).

The product of its digits is 186624, while the sum is 36.

The square root of 644334363 is about 25383.7421000135. The cubic root of 644334363 is about 863.7149385919.

The spelling of 644334363 in words is "six hundred forty-four million, three hundred thirty-four thousand, three hundred sixty-three".