636138384 has 120 divisors (see below), whose sum is σ = 1920064608. Its totient is φ = 180956160.

The previous prime is 636138367. The next prime is 636138397. The reversal of 636138384 is 483831636.

636138384 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 (42).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 721624 + ... + 722504.

Almost surely, 2^636138384 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 636138384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (960032304).

636138384 is an abundant number, since it is smaller than the sum of its proper divisors (1283926224).

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

636138384 is a wasteful number, since it uses less digits than its factorization.

636138384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1213 (or 1200 counting only the distinct ones).

The product of its digits is 248832, while the sum is 42.

The square root of 636138384 is about 25221.7839178754. The cubic root of 636138384 is about 860.0371283772.

The spelling of 636138384 in words is "six hundred thirty-six million, one hundred thirty-eight thousand, three hundred eighty-four".