22121211221 has 2 divisors, whose sum is σ = 22121211222. Its totient is φ = 22121211220.

The previous prime is 22121211209. The next prime is 22121211251. The reversal of 22121211221 is 12211212122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21835972900 + 285238321 = 147770^2 + 16889^2 .

It is a cyclic number.

It is not a de Polignac number, because 22121211221 - 2⁶ = 22121211157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22121211221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22121211251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11060605610 + 11060605611.

It is an arithmetic number, because the mean of its divisors is an integer number (11060605611).

Almost surely, 2^22121211221 is an apocalyptic number.

It is an amenable number.

22121211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22121211221 is an equidigital number, since it uses as much as digits as its factorization.

22121211221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 17.

Adding to 22121211221 its reverse (12211212122), we get a palindrome (34332423343).

Subtracting from 22121211221 its reverse (12211212122), we obtain a palindrome (9909999099).

The spelling of 22121211221 in words is "twenty-two billion, one hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".