12221121221 has 2 divisors, whose sum is σ = 12221121222. Its totient is φ = 12221121220.

The previous prime is 12221121197. The next prime is 12221121239. The reversal of 12221121221 is 12212112221.

12221121221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11987184196 + 233937025 = 109486^2 + 15295^2 .

It is a cyclic number.

It is not a de Polignac number, because 12221121221 - 2¹⁴ = 12221104837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12221121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12221121281) 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, 6110560610 + 6110560611.

It is an arithmetic number, because the mean of its divisors is an integer number (6110560611).

Almost surely, 2^12221121221 is an apocalyptic number.

It is an amenable number.

12221121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12221121221 is an equidigital number, since it uses as much as digits as its factorization.

12221121221 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 12221121221 its reverse (12212112221), we get a palindrome (24433233442).

It can be divided in two parts, 12221 and 121221, that multiplied together give a palindrome (1481441841).

The spelling of 12221121221 in words is "twelve billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".