636889 has 4 divisors (see below), whose sum is σ = 694800. Its totient is φ = 578980.

The previous prime is 636877. The next prime is 636917. The reversal of 636889 is 988636.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 636889 - 2⁷ = 636761 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 a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28939 + ... + 28960.

It is an arithmetic number, because the mean of its divisors is an integer number (173700).

2⁶³⁶⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

636889 is a deficient number, since it is larger than the sum of its proper divisors (57911).

636889 is a wasteful number, since it uses less digits than its factorization.

636889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57910.

The product of its digits is 62208, while the sum is 40.

The square root of 636889 is about 798.0532563683. The cubic root of 636889 is about 86.0375264387.

The spelling of 636889 in words is "six hundred thirty-six thousand, eight hundred eighty-nine".