11636165621 has 4 divisors (see below), whose sum is σ = 11739140652. Its totient is φ = 11533190592.

The previous prime is 11636165609. The next prime is 11636165641. The reversal of 11636165621 is 12656163611.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3415116721 + 8221048900 = 58439^2 + 90670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11636165621 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 (11636165641) 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, 51487346 + ... + 51487571.

It is an arithmetic number, because the mean of its divisors is an integer number (2934785163).

Almost surely, 2^11636165621 is an apocalyptic number.

It is an amenable number.

11636165621 is a deficient number, since it is larger than the sum of its proper divisors (102975031).

11636165621 is a wasteful number, since it uses less digits than its factorization.

11636165621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102975030.

The product of its digits is 38880, while the sum is 38.

The spelling of 11636165621 in words is "eleven billion, six hundred thirty-six million, one hundred sixty-five thousand, six hundred twenty-one".