639804384 has 108 divisors (see below), whose sum is σ = 1933016904. Its totient is φ = 200696832.

The previous prime is 639804349. The next prime is 639804427. The reversal of 639804384 is 483408936.

639804384 is a `hidden beast` number, since 639 + 8 + 0 + 4 + 3 + 8 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 79389 + ... + 87075.

Almost surely, 2^639804384 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 639804384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (966508452).

639804384 is an abundant number, since it is smaller than the sum of its proper divisors (1293212520).

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

639804384 is a wasteful number, since it uses less digits than its factorization.

639804384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7737 (or 7709 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 639804384 is about 25294.3547852085. The cubic root of 639804384 is about 861.6860666708.

The spelling of 639804384 in words is "six hundred thirty-nine million, eight hundred four thousand, three hundred eighty-four".