644434234 has 4 divisors (see below), whose sum is σ = 966651354. Its totient is φ = 322217116.

The previous prime is 644434213. The next prime is 644434243. The reversal of 644434234 is 432434446.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 434097225 + 210337009 = 20835^2 + 14503^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 644434234.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161108557 + ... + 161108560.

Almost surely, 2^644434234 is an apocalyptic number.

644434234 is a deficient number, since it is larger than the sum of its proper divisors (322217120).

644434234 is a wasteful number, since it uses less digits than its factorization.

644434234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322217119.

The product of its digits is 110592, while the sum is 34.

The square root of 644434234 is about 25385.7092475274. The cubic root of 644434234 is about 863.7595611891.

The spelling of 644434234 in words is "six hundred forty-four million, four hundred thirty-four thousand, two hundred thirty-four".