636538386468 has 12 divisors (see below), whose sum is σ = 1485256235120. Its totient is φ = 212179462152.

The previous prime is 636538386413. The next prime is 636538386469. The reversal of 636538386468 is 864683835636.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×636538386468² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 636538386399 and 636538386408.

It is not an unprimeable number, because it can be changed into a prime (636538386469) 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, 26522432758 + ... + 26522432781.

Almost surely, 2^636538386468 is an apocalyptic number.

It is an amenable number.

636538386468 is an abundant number, since it is smaller than the sum of its proper divisors (848717848652).

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

636538386468 is a wasteful number, since it uses less digits than its factorization.

636538386468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53044865546 (or 53044865544 counting only the distinct ones).

The product of its digits is 358318080, while the sum is 66.

The spelling of 636538386468 in words is "six hundred thirty-six billion, five hundred thirty-eight million, three hundred eighty-six thousand, four hundred sixty-eight".