12222122221 has 2 divisors, whose sum is σ = 12222122222. Its totient is φ = 12222122220.

The previous prime is 12222122207. The next prime is 12222122249.

12222122221 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12155062500 + 67059721 = 110250^2 + 8189^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 12222122221 - 2⁵ = 12222122189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12222122201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6111061110 + 6111061111.

It is an arithmetic number, because the mean of its divisors is an integer number (6111061111).

Almost surely, 2^12222122221 is an apocalyptic number.

It is an amenable number.

12222122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12222122221 is an equidigital number, since it uses as much as digits as its factorization.

12222122221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256, while the sum is 19.

The spelling of 12222122221 in words is "twelve billion, two hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".