21222002220121 has 2 divisors, whose sum is σ = 21222002220122. Its totient is φ = 21222002220120.

The previous prime is 21222002220119. The next prime is 21222002220173. The reversal of 21222002220121 is 12102220022212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15925399160896 + 5296603059225 = 3990664^2 + 2301435^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222002220121 - 2¹ = 21222002220119 is a prime.

Together with 21222002220119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21222002227121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611001110060 + 10611001110061.

It is an arithmetic number, because the mean of its divisors is an integer number (10611001110061).

Almost surely, 2^{21222002220121} is an apocalyptic number.

It is an amenable number.

21222002220121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222002220121 is an equidigital number, since it uses as much as digits as its factorization.

21222002220121 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21222002220121 its reverse (12102220022212), we get a palindrome (33324222242333).

The spelling of 21222002220121 in words is "twenty-one trillion, two hundred twenty-two billion, two million, two hundred twenty thousand, one hundred twenty-one".