21222221211211 has 2 divisors, whose sum is σ = 21222221211212. Its totient is φ = 21222221211210.

The previous prime is 21222221211187. The next prime is 21222221211221. The reversal of 21222221211211 is 11211212222212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21222221211211 - 2¹³ = 21222221203019 is a prime.

It is not a weakly prime, because it can be changed into another prime (21222221211221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611110605605 + 10611110605606.

It is an arithmetic number, because the mean of its divisors is an integer number (10611110605606).

Almost surely, 2^{21222221211211} is an apocalyptic number.

21222221211211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222221211211 is an equidigital number, since it uses as much as digits as its factorization.

21222221211211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 256, while the sum is 22.

Adding to 21222221211211 its reverse (11211212222212), we get a palindrome (32433433433423).

The spelling of 21222221211211 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty-one million, two hundred eleven thousand, two hundred eleven".