636385 has 4 divisors (see below), whose sum is σ = 763668. Its totient is φ = 509104.

The previous prime is 636359. The next prime is 636403. The reversal of 636385 is 583636.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 389376 + 247009 = 624^2 + 497^2 .

It is a cyclic number.

It is not a de Polignac number, because 636385 - 2⁵ = 636353 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 63634 + ... + 63643.

It is an arithmetic number, because the mean of its divisors is an integer number (190917).

2⁶³⁶³⁸⁵ is an apocalyptic number.

It is an amenable number.

636385 is a deficient number, since it is larger than the sum of its proper divisors (127283).

636385 is a wasteful number, since it uses less digits than its factorization.

636385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127282.

The product of its digits is 12960, while the sum is 31.

The square root of 636385 is about 797.7374254728. The cubic root of 636385 is about 86.0148252790.

The spelling of 636385 in words is "six hundred thirty-six thousand, three hundred eighty-five".