21182371436161 has 4 divisors (see below), whose sum is σ = 22811784623572. Its totient is φ = 19552958248752.

The previous prime is 21182371436153. The next prime is 21182371436173. The reversal of 21182371436161 is 16163417328112.

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 9916950476161 + 11265420960000 = 3149119^2 + 3356400^2 .

It is a cyclic number.

It is not a de Polignac number, because 21182371436161 - 2³ = 21182371436153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21182371436461) 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 3 ways as a sum of consecutive naturals, for example, 814706593686 + ... + 814706593711.

It is an arithmetic number, because the mean of its divisors is an integer number (5702946155893).

Almost surely, 2^{21182371436161} is an apocalyptic number.

It is an amenable number.

21182371436161 is a deficient number, since it is larger than the sum of its proper divisors (1629413187411).

21182371436161 is a wasteful number, since it uses less digits than its factorization.

21182371436161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629413187410.

The product of its digits is 290304, while the sum is 46.

The spelling of 21182371436161 in words is "twenty-one trillion, one hundred eighty-two billion, three hundred seventy-one million, four hundred thirty-six thousand, one hundred sixty-one".