21222111100121 has 2 divisors, whose sum is σ = 21222111100122. Its totient is φ = 21222111100120.

The previous prime is 21222111100063. The next prime is 21222111100129. The reversal of 21222111100121 is 12100111122212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11957764000000 + 9264347100121 = 3458000^2 + 3043739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222111100121 - 2³⁸ = 20947233193177 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21222111100121.

It is not a weakly prime, because it can be changed into another prime (21222111100129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611055550060 + 10611055550061.

It is an arithmetic number, because the mean of its divisors is an integer number (10611055550061).

Almost surely, 2^{21222111100121} is an apocalyptic number.

It is an amenable number.

21222111100121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222111100121 is an equidigital number, since it uses as much as digits as its factorization.

21222111100121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21222111100121 its reverse (12100111122212), we get a palindrome (33322222222333).

The spelling of 21222111100121 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, one hundred thousand, one hundred twenty-one".