644052620 has 12 divisors (see below), whose sum is σ = 1352510544. Its totient is φ = 257621040.

The previous prime is 644052611. The next prime is 644052623. The reversal of 644052620 is 26250446.

644052620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (644052623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16101296 + ... + 16101335.

It is an arithmetic number, because the mean of its divisors is an integer number (112709212).

Almost surely, 2^644052620 is an apocalyptic number.

It is an amenable number.

644052620 is an abundant number, since it is smaller than the sum of its proper divisors (708457924).

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

644052620 is a wasteful number, since it uses less digits than its factorization.

644052620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32202640 (or 32202638 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 644052620 is about 25378.1918189614. The cubic root of 644052620 is about 863.5890303010.

The spelling of 644052620 in words is "six hundred forty-four million, fifty-two thousand, six hundred twenty".