636404 has 12 divisors (see below), whose sum is σ = 1119300. Its totient is φ = 316608.

The previous prime is 636403. The next prime is 636407. The reversal of 636404 is 404636.

It can be written as a sum of positive squares in 2 ways, for example, as 384400 + 252004 = 620^2 + 502^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 636404.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 636404.

It is not an unprimeable number, because it can be changed into a prime (636403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1352 + ... + 1760.

It is an arithmetic number, because the mean of its divisors is an integer number (93275).

2⁶³⁶⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

636404 is a deficient number, since it is larger than the sum of its proper divisors (482896).

636404 is a wasteful number, since it uses less digits than its factorization.

636404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802 (or 800 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 636404 is about 797.7493340643. The cubic root of 636404 is about 86.0156812941.

The spelling of 636404 in words is "six hundred thirty-six thousand, four hundred four".