211122122221 has 2 divisors, whose sum is σ = 211122122222. Its totient is φ = 211122122220.

The previous prime is 211122122203. The next prime is 211122122227. The reversal of 211122122221 is 122221221112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154988666596 + 56133455625 = 393686^2 + 236925^2 .

It is a cyclic number.

It is not a de Polignac number, because 211122122221 - 2¹⁹ = 211121597933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211122122227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105561061110 + 105561061111.

It is an arithmetic number, because the mean of its divisors is an integer number (105561061111).

Almost surely, 2^211122122221 is an apocalyptic number.

It is an amenable number.

211122122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

211122122221 is an equidigital number, since it uses as much as digits as its factorization.

211122122221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 19.

Adding to 211122122221 its reverse (122221221112), we get a palindrome (333343343333).

The spelling of 211122122221 in words is "two hundred eleven billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".