21102111120121 has 2 divisors, whose sum is σ = 21102111120122. Its totient is φ = 21102111120120.

The previous prime is 21102111120073. The next prime is 21102111120133. The reversal of 21102111120121 is 12102111120112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19956277890025 + 1145833230096 = 4467245^2 + 1070436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102111120121 - 2¹⁵ = 21102111087353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21102111120095 and 21102111120104.

It is not a weakly prime, because it can be changed into another prime (21102111120521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551055560060 + 10551055560061.

It is an arithmetic number, because the mean of its divisors is an integer number (10551055560061).

Almost surely, 2^{21102111120121} is an apocalyptic number.

It is an amenable number.

21102111120121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102111120121 is an equidigital number, since it uses as much as digits as its factorization.

21102111120121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21102111120121 its reverse (12102111120112), we get a palindrome (33204222240233).

Subtracting from 21102111120121 its reverse (12102111120112), we obtain a palindrome (9000000000009).

The spelling of 21102111120121 in words is "twenty-one trillion, one hundred two billion, one hundred eleven million, one hundred twenty thousand, one hundred twenty-one".