636575866864 has 40 divisors (see below), whose sum is σ = 1414577148768. Its totient is φ = 271847331840.

The previous prime is 636575866841. The next prime is 636575866879. The reversal of 636575866864 is 468668575636.

It is a junction number, because it is equal to n+sod(n) for n = 636575866793 and 636575866802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10081897 + ... + 10144840.

Almost surely, 2^636575866864 is an apocalyptic number.

It is an amenable number.

636575866864 is an abundant number, since it is smaller than the sum of its proper divisors (778001281904).

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

636575866864 is a wasteful number, since it uses less digits than its factorization.

636575866864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20227033 (or 20227027 counting only the distinct ones).

The product of its digits is 1045094400, while the sum is 70.

The spelling of 636575866864 in words is "six hundred thirty-six billion, five hundred seventy-five million, eight hundred sixty-six thousand, eight hundred sixty-four".