644270848 has 144 divisors (see below), whose sum is σ = 1524660480. Its totient is φ = 268849152.

The previous prime is 644270839. The next prime is 644270881. The reversal of 644270848 is 848072446.

It is a congruent number.

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, 1454115 + ... + 1454557.

It is an arithmetic number, because the mean of its divisors is an integer number (10587920).

Almost surely, 2^644270848 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 644270848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (762330240).

644270848 is an abundant number, since it is smaller than the sum of its proper divisors (880389632).

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

644270848 is a wasteful number, since it uses less digits than its factorization.

644270848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514 (or 500 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 43.

The square root of 644270848 is about 25382.4909731098. The cubic root of 644270848 is about 863.6865575420.

The spelling of 644270848 in words is "six hundred forty-four million, two hundred seventy thousand, eight hundred forty-eight".