11638135661 has 16 divisors (see below), whose sum is σ = 12143623680. Its totient is φ = 11141091840.

The previous prime is 11638135633. The next prime is 11638135681. The reversal of 11638135661 is 16653183611.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 11638135661 - 2¹⁴ = 11638119277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11638135681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2681285 + ... + 2685621.

It is an arithmetic number, because the mean of its divisors is an integer number (758976480).

Almost surely, 2^11638135661 is an apocalyptic number.

It is an amenable number.

11638135661 is a deficient number, since it is larger than the sum of its proper divisors (505488019).

11638135661 is a wasteful number, since it uses less digits than its factorization.

11638135661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5284.

The product of its digits is 77760, while the sum is 41.

The spelling of 11638135661 in words is "eleven billion, six hundred thirty-eight million, one hundred thirty-five thousand, six hundred sixty-one".