21233122121 has 2 divisors, whose sum is σ = 21233122122. Its totient is φ = 21233122120.

The previous prime is 21233122103. The next prime is 21233122123. The reversal of 21233122121 is 12122133212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13939108096 + 7294014025 = 118064^2 + 85405^2 .

It is a cyclic number.

It is not a de Polignac number, because 21233122121 - 2³⁴ = 4053252937 is a prime.

It is a super-3 number, since 3×21233122121³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 21233122123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21233122093 and 21233122102.

It is not a weakly prime, because it can be changed into another prime (21233122123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616561060 + 10616561061.

It is an arithmetic number, because the mean of its divisors is an integer number (10616561061).

Almost surely, 2^21233122121 is an apocalyptic number.

It is an amenable number.

21233122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233122121 is an equidigital number, since it uses as much as digits as its factorization.

21233122121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 20.

Adding to 21233122121 its reverse (12122133212), we get a palindrome (33355255333).

The spelling of 21233122121 in words is "twenty-one billion, two hundred thirty-three million, one hundred twenty-two thousand, one hundred twenty-one".