636808424868 has 72 divisors (see below), whose sum is σ = 2006911408320. Its totient is φ = 165404784960.

The previous prime is 636808424807. The next prime is 636808424873. The reversal of 636808424868 is 868424808636.

It is a happy number.

636808424868 is a `hidden beast` number, since 6 + 36 + 80 + 8 + 42 + 486 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114861663 + ... + 114867206.

It is an arithmetic number, because the mean of its divisors is an integer number (27873769560).

Almost surely, 2^636808424868 is an apocalyptic number.

It is an amenable number.

636808424868 is an abundant number, since it is smaller than the sum of its proper divisors (1370102983452).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

636808424868 is a wasteful number, since it uses less digits than its factorization.

636808424868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229728897 (or 229728892 counting only the distinct ones).

The product of its (nonzero) digits is 84934656, while the sum is 63.

The spelling of 636808424868 in words is "six hundred thirty-six billion, eight hundred eight million, four hundred twenty-four thousand, eight hundred sixty-eight".