636799 has 4 divisors (see below), whose sum is σ = 645840. Its totient is φ = 627760.

The previous prime is 636781. The next prime is 636809. The reversal of 636799 is 997636.

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

It is a cyclic number.

It is not a de Polignac number, because 636799 - 2⁹ = 636287 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (636719) 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, 4414 + ... + 4555.

It is an arithmetic number, because the mean of its divisors is an integer number (161460).

2⁶³⁶⁷⁹⁹ is an apocalyptic number.

636799 is a deficient number, since it is larger than the sum of its proper divisors (9041).

636799 is an equidigital number, since it uses as much as digits as its factorization.

636799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9040.

The product of its digits is 61236, while the sum is 40.

The square root of 636799 is about 797.9968671618. The cubic root of 636799 is about 86.0334735388.

The spelling of 636799 in words is "six hundred thirty-six thousand, seven hundred ninety-nine".