636090813 has 10 divisors (see below), whose sum is σ = 950209854. Its totient is φ = 424060488.

The previous prime is 636090779. The next prime is 636090841. The reversal of 636090813 is 318090636.

It is a happy number.

636090813 is a `hidden beast` number, since 636 + 0 + 9 + 0 + 8 + 13 = 666.

It can be written as a sum of positive squares in only one way, i.e., 600593049 + 35497764 = 24507^2 + 5958^2 .

It is not a de Polignac number, because 636090813 - 2⁸ = 636090557 is a prime.

It is a super-2 number, since 2×636090813² = 809223044766001938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636050813) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3926406 + ... + 3926567.

Almost surely, 2^636090813 is an apocalyptic number.

It is an amenable number.

636090813 is a deficient number, since it is larger than the sum of its proper divisors (314119041).

636090813 is an equidigital number, since it uses as much as digits as its factorization.

636090813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7852985 (or 7852976 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 636090813 is about 25220.8408464111. The cubic root of 636090813 is about 860.0156897264.

The spelling of 636090813 in words is "six hundred thirty-six million, ninety thousand, eight hundred thirteen".