644060986008 has 256 divisors, whose sum is σ = 1860209971200. Its totient is φ = 183779228160.

The previous prime is 644060986007. The next prime is 644060986021. The reversal of 644060986008 is 800689060446.

644060986008 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644060986007) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1001649735 + ... + 1001650377.

It is an arithmetic number, because the mean of its divisors is an integer number (7266445200).

Almost surely, 2^644060986008 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 644060986008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930104985600).

644060986008 is an abundant number, since it is smaller than the sum of its proper divisors (1216148985192).

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

644060986008 is a wasteful number, since it uses less digits than its factorization.

644060986008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1582 (or 1578 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 51.

The spelling of 644060986008 in words is "six hundred forty-four billion, sixty million, nine hundred eighty-six thousand, eight".