644963088 has 240 divisors, whose sum is σ = 2144487744. Its totient is φ = 165150720.

The previous prime is 644963083. The next prime is 644963089. The reversal of 644963088 is 880369446.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (644963083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2509456 + ... + 2509712.

Almost surely, 2^644963088 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 644963088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1072243872).

644963088 is an abundant number, since it is smaller than the sum of its proper divisors (1499524656).

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

644963088 is a wasteful number, since it uses less digits than its factorization.

644963088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 48.

The square root of 644963088 is about 25396.1234837130. The cubic root of 644963088 is about 863.9957775857.

The spelling of 644963088 in words is "six hundred forty-four million, nine hundred sixty-three thousand, eighty-eight".