12122211221 has 2 divisors, whose sum is σ = 12122211222. Its totient is φ = 12122211220.

The previous prime is 12122211217. The next prime is 12122211259. The reversal of 12122211221 is 12211222121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10881410596 + 1240800625 = 104314^2 + 35225^2 .

It is a cyclic number.

It is not a de Polignac number, because 12122211221 - 2² = 12122211217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12122211221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12122211281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6061105610 + 6061105611.

It is an arithmetic number, because the mean of its divisors is an integer number (6061105611).

Almost surely, 2^12122211221 is an apocalyptic number.

It is an amenable number.

12122211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12122211221 is an equidigital number, since it uses as much as digits as its factorization.

12122211221 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 12122211221 its reverse (12211222121), we get a palindrome (24333433342).

The spelling of 12122211221 in words is "twelve billion, one hundred twenty-two million, two hundred eleven thousand, two hundred twenty-one".