639313344 has 112 divisors (see below), whose sum is σ = 1901037600. Its totient is φ = 210659328.

The previous prime is 639313309. The next prime is 639313351. The reversal of 639313344 is 443313936.

639313344 is a `hidden beast` number, since 639 + 3 + 13 + 3 + 4 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 639313299 and 639313308.

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, 151714 + ... + 155870.

It is an arithmetic number, because the mean of its divisors is an integer number (16973550).

Almost surely, 2^639313344 is an apocalyptic number.

639313344 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639313344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (950518800).

639313344 is an abundant number, since it is smaller than the sum of its proper divisors (1261724256).

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

639313344 is a wasteful number, since it uses less digits than its factorization.

639313344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4267 (or 4251 counting only the distinct ones).

The product of its digits is 69984, while the sum is 36.

The square root of 639313344 is about 25284.6464084432. The cubic root of 639313344 is about 861.4655666609.

The spelling of 639313344 in words is "six hundred thirty-nine million, three hundred thirteen thousand, three hundred forty-four".