644033652 has 24 divisors (see below), whose sum is σ = 1581837600. Its totient is φ = 203378976.

The previous prime is 644033641. The next prime is 644033659. The reversal of 644033652 is 256330446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644033659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1412127 + ... + 1412582.

It is an arithmetic number, because the mean of its divisors is an integer number (65909900).

Almost surely, 2^644033652 is an apocalyptic number.

It is an amenable number.

644033652 is an abundant number, since it is smaller than the sum of its proper divisors (937803948).

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

644033652 is a wasteful number, since it uses less digits than its factorization.

644033652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824735 (or 2824733 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 33.

The square root of 644033652 is about 25377.8181095223. The cubic root of 644033652 is about 863.5805523615.

The spelling of 644033652 in words is "six hundred forty-four million, thirty-three thousand, six hundred fifty-two".