644527812 has 24 divisors (see below), whose sum is σ = 1504381536. Its totient is φ = 214773568.

The previous prime is 644527811. The next prime is 644527837. The reversal of 644527812 is 218725446.

644527812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×644527812² = 830832200883014688, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (644527811) 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, 42283 + ... + 55469.

It is an arithmetic number, because the mean of its divisors is an integer number (62682564).

Almost surely, 2^644527812 is an apocalyptic number.

It is an amenable number.

644527812 is an abundant number, since it is smaller than the sum of its proper divisors (859853724).

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

644527812 is a wasteful number, since it uses less digits than its factorization.

644527812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17267 (or 17265 counting only the distinct ones).

The product of its digits is 107520, while the sum is 39.

The square root of 644527812 is about 25387.5523042297. The cubic root of 644527812 is about 863.8013678757.

The spelling of 644527812 in words is "six hundred forty-four million, five hundred twenty-seven thousand, eight hundred twelve".