11356636681 has 4 divisors (see below), whose sum is σ = 12230224132. Its totient is φ = 10483049232.

The previous prime is 11356636663. The next prime is 11356636693. The reversal of 11356636681 is 18663665311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18663665311 = 1277 ⋅14615243.

It can be written as a sum of positive squares in 2 ways, for example, as 4393568656 + 6963068025 = 66284^2 + 83445^2 .

It is a cyclic number.

It is not a de Polignac number, because 11356636681 - 2⁹ = 11356636169 is a prime.

It is a super-2 number, since 2×11356636681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11356636481) 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, 436793706 + ... + 436793731.

It is an arithmetic number, because the mean of its divisors is an integer number (3057556033).

Almost surely, 2^11356636681 is an apocalyptic number.

It is an amenable number.

11356636681 is a deficient number, since it is larger than the sum of its proper divisors (873587451).

11356636681 is an equidigital number, since it uses as much as digits as its factorization.

11356636681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873587450.

The product of its digits is 466560, while the sum is 46.

The spelling of 11356636681 in words is "eleven billion, three hundred fifty-six million, six hundred thirty-six thousand, six hundred eighty-one".