636748836 has 72 divisors (see below), whose sum is σ = 1595719104. Its totient is φ = 197461440.

The previous prime is 636748811. The next prime is 636748841. The reversal of 636748836 is 638847636.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 233521 + ... + 236231.

Almost surely, 2^636748836 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 636748836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (797859552).

636748836 is an abundant number, since it is smaller than the sum of its proper divisors (958970268).

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

636748836 is a wasteful number, since it uses less digits than its factorization.

636748836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2801 (or 2776 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 51.

The square root of 636748836 is about 25233.8826976746. The cubic root of 636748836 is about 860.3121437672.

The spelling of 636748836 in words is "six hundred thirty-six million, seven hundred forty-eight thousand, eight hundred thirty-six".