644626092 has 48 divisors (see below), whose sum is σ = 1653829632. Its totient is φ = 193798080.

The previous prime is 644626063. The next prime is 644626133. The reversal of 644626092 is 290626446.

644626092 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 644626092.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2463 + ... + 35990.

It is an arithmetic number, because the mean of its divisors is an integer number (34454784).

Almost surely, 2^644626092 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644626092, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (826914816).

644626092 is an abundant number, since it is smaller than the sum of its proper divisors (1009203540).

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

644626092 is a wasteful number, since it uses less digits than its factorization.

644626092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38598 (or 38596 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 39.

The square root of 644626092 is about 25389.4878246884. The cubic root of 644626092 is about 863.8452708603.

The spelling of 644626092 in words is "six hundred forty-four million, six hundred twenty-six thousand, ninety-two".