636320263681 has 4 divisors (see below), whose sum is σ = 651118409392. Its totient is φ = 621522117972.

The previous prime is 636320263673. The next prime is 636320263687. The reversal of 636320263681 is 186362023636.

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 636320263681 - 2³ = 636320263673 is a prime.

It is a super-2 number, since 2×636320263681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (636320263687) 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, 7399072791 + ... + 7399072876.

It is an arithmetic number, because the mean of its divisors is an integer number (162779602348).

Almost surely, 2^636320263681 is an apocalyptic number.

It is an amenable number.

636320263681 is a deficient number, since it is larger than the sum of its proper divisors (14798145711).

636320263681 is a wasteful number, since it uses less digits than its factorization.

636320263681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14798145710.

The product of its (nonzero) digits is 1119744, while the sum is 46.

The spelling of 636320263681 in words is "six hundred thirty-six billion, three hundred twenty million, two hundred sixty-three thousand, six hundred eighty-one".