644412080 has 80 divisors (see below), whose sum is σ = 1620458784. Its totient is φ = 236912640.

The previous prime is 644412079. The next prime is 644412133. The reversal of 644412080 is 80214446.

It is a tau number, because it is divible by the number of its divisors (80).

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, 266075 + ... + 268485.

Almost surely, 2^644412080 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 644412080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (810229392).

644412080 is an abundant number, since it is smaller than the sum of its proper divisors (976046704).

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

644412080 is a wasteful number, since it uses less digits than its factorization.

644412080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694 (or 2688 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 644412080 is about 25385.2728959135. The cubic root of 644412080 is about 863.7496631278.

It can be divided in two parts, 64 and 4412080, that added together give a palindrome (4412144).

The spelling of 644412080 in words is "six hundred forty-four million, four hundred twelve thousand, eighty".