12221221121 has 2 divisors, whose sum is σ = 12221221122. Its totient is φ = 12221221120.

The previous prime is 12221221091. The next prime is 12221221127. The reversal of 12221221121 is 12112212221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11170164721 + 1051056400 = 105689^2 + 32420^2 .

It is a cyclic number.

It is not a de Polignac number, because 12221221121 - 2¹⁸ = 12220958977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12221221121.

It is not a weakly prime, because it can be changed into another prime (12221221127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6110610560 + 6110610561.

It is an arithmetic number, because the mean of its divisors is an integer number (6110610561).

Almost surely, 2^12221221121 is an apocalyptic number.

It is an amenable number.

12221221121 is a deficient number, since it is larger than the sum of its proper divisors (1).

12221221121 is an equidigital number, since it uses as much as digits as its factorization.

12221221121 is an evil number, because the sum of its binary digits is even.

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

Adding to 12221221121 its reverse (12112212221), we get a palindrome (24333433342).

The spelling of 12221221121 in words is "twelve billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".