644734530 has 48 divisors (see below), whose sum is σ = 1828704384. Its totient is φ = 156299040.

The previous prime is 644734513. The next prime is 644734567. The reversal of 644734530 is 35437446.

It is a happy number.

644734530 is a `hidden beast` number, since 644 + 7 + 3 + 4 + 5 + 3 + 0 = 666.

It is a super-2 number, since 2×644734530² = 831365228348641800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 324634 + ... + 326613.

It is an arithmetic number, because the mean of its divisors is an integer number (38098008).

Almost surely, 2^644734530 is an apocalyptic number.

644734530 is an abundant number, since it is smaller than the sum of its proper divisors (1183969854).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644734530 is a wasteful number, since it uses less digits than its factorization.

644734530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651271 (or 651268 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 36.

The square root of 644734530 is about 25391.6232249929. The cubic root of 644734530 is about 863.8937063811.

The spelling of 644734530 in words is "six hundred forty-four million, seven hundred thirty-four thousand, five hundred thirty".