22161876721 has 2 divisors, whose sum is σ = 22161876722. Its totient is φ = 22161876720.

The previous prime is 22161876713. The next prime is 22161876731. The reversal of 22161876721 is 12767816122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12379677696 + 9782199025 = 111264^2 + 98905^2 .

It is a cyclic number.

It is not a de Polignac number, because 22161876721 - 2³ = 22161876713 is a prime.

It is a super-2 number, since 2×22161876721² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (22161876731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11080938360 + 11080938361.

It is an arithmetic number, because the mean of its divisors is an integer number (11080938361).

Almost surely, 2^22161876721 is an apocalyptic number.

It is an amenable number.

22161876721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22161876721 is an equidigital number, since it uses as much as digits as its factorization.

22161876721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 43.

The spelling of 22161876721 in words is "twenty-two billion, one hundred sixty-one million, eight hundred seventy-six thousand, seven hundred twenty-one".