639867384 has 64 divisors (see below), whose sum is σ = 1914141600. Its totient is φ = 196881408.

The previous prime is 639867377. The next prime is 639867409. The reversal of 639867384 is 483768936.

639867384 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 639867384.

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, 111129 + ... + 116744.

Almost surely, 2^639867384 is an apocalyptic number.

It is an amenable number.

639867384 is an abundant number, since it is smaller than the sum of its proper divisors (1274274216).

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

639867384 is a wasteful number, since it uses less digits than its factorization.

639867384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227901 (or 227891 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 54.

The square root of 639867384 is about 25295.6000917156. The cubic root of 639867384 is about 861.7143484612.

The spelling of 639867384 in words is "six hundred thirty-nine million, eight hundred sixty-seven thousand, three hundred eighty-four".