644948096 has 128 divisors (see below), whose sum is σ = 1443536640. Its totient is φ = 285143040.

The previous prime is 644948093. The next prime is 644948107. The reversal of 644948096 is 690849446.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (644948093) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6261581 + ... + 6261683.

It is an arithmetic number, because the mean of its divisors is an integer number (11277630).

Almost surely, 2^644948096 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 644948096, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (721768320).

644948096 is an abundant number, since it is smaller than the sum of its proper divisors (798588544).

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

644948096 is a wasteful number, since it uses less digits than its factorization.

644948096 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 50.

The square root of 644948096 is about 25395.8283188401. The cubic root of 644948096 is about 863.9890830811.

It can be divided in two parts, 6449 and 48096, that added together give a palindrome (54545).

The spelling of 644948096 in words is "six hundred forty-four million, nine hundred forty-eight thousand, ninety-six".