644320050 has 96 divisors (see below), whose sum is σ = 1765601280. Its totient is φ = 154190400.

The previous prime is 644320049. The next prime is 644320051. The reversal of 644320050 is 50023446.

644320050 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (644320049) and next prime (644320051).

It is a self number, because there is not a number n which added to its sum of digits gives 644320050.

It is not an unprimeable number, because it can be changed into a prime (644320051) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 127879 + ... + 132821.

It is an arithmetic number, because the mean of its divisors is an integer number (18391680).

Almost surely, 2^644320050 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644320050, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (882800640).

644320050 is an abundant number, since it is smaller than the sum of its proper divisors (1121281230).

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

644320050 is a wasteful number, since it uses less digits than its factorization.

644320050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5048 (or 5043 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 24.

The square root of 644320050 is about 25383.4601660215. The cubic root of 644320050 is about 863.7085431321.

Adding to 644320050 its reverse (50023446), we get a palindrome (694343496).

The spelling of 644320050 in words is "six hundred forty-four million, three hundred twenty thousand, fifty".