644437514 has 12 divisors (see below), whose sum is σ = 1124477874. Its totient is φ = 276187464.

The previous prime is 644437501. The next prime is 644437537. The reversal of 644437514 is 415734446.

It can be written as a sum of positive squares in only one way, i.e., 601966225 + 42471289 = 24535^2 + 6517^2 .

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 5 ways as a sum of consecutive naturals, for example, 3287849 + ... + 3288044.

Almost surely, 2^644437514 is an apocalyptic number.

644437514 is a deficient number, since it is larger than the sum of its proper divisors (480040360).

644437514 is a wasteful number, since it uses less digits than its factorization.

644437514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6575909 (or 6575902 counting only the distinct ones).

The product of its digits is 161280, while the sum is 38.

The square root of 644437514 is about 25385.7738507220. The cubic root of 644437514 is about 863.7610266226.

The spelling of 644437514 in words is "six hundred forty-four million, four hundred thirty-seven thousand, five hundred fourteen".