12221221321 has 2 divisors, whose sum is σ = 12221221322. Its totient is φ = 12221221320.

The previous prime is 12221221319. The next prime is 12221221333. The reversal of 12221221321 is 12312212221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8887775625 + 3333445696 = 94275^2 + 57736^2 .

It is a cyclic number.

It is not a de Polignac number, because 12221221321 - 2¹ = 12221221319 is a prime.

Together with 12221221319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12221221121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6110610660 + 6110610661.

It is an arithmetic number, because the mean of its divisors is an integer number (6110610661).

Almost surely, 2^12221221321 is an apocalyptic number.

It is an amenable number.

12221221321 is a deficient number, since it is larger than the sum of its proper divisors (1).

12221221321 is an equidigital number, since it uses as much as digits as its factorization.

12221221321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 19.

Adding to 12221221321 its reverse (12312212221), we get a palindrome (24533433542).

The spelling of 12221221321 in words is "twelve billion, two hundred twenty-one million, two hundred twenty-one thousand, three hundred twenty-one".