21122022121 has 2 divisors, whose sum is σ = 21122022122. Its totient is φ = 21122022120.

The previous prime is 21122022109. The next prime is 21122022127. The reversal of 21122022121 is 12122022112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14686773721 + 6435248400 = 121189^2 + 80220^2 .

It is a cyclic number.

It is not a de Polignac number, because 21122022121 - 2¹³ = 21122013929 is a prime.

It is a super-2 number, since 2×21122022121² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122022095 and 21122022104.

It is not a weakly prime, because it can be changed into another prime (21122022127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561011060 + 10561011061.

It is an arithmetic number, because the mean of its divisors is an integer number (10561011061).

Almost surely, 2^21122022121 is an apocalyptic number.

It is an amenable number.

21122022121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122022121 is an equidigital number, since it uses as much as digits as its factorization.

21122022121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21122022121 its reverse (12122022112), we get a palindrome (33244044233).

Subtracting from 21122022121 its reverse (12122022112), we obtain a palindrome (9000000009).

The spelling of 21122022121 in words is "twenty-one billion, one hundred twenty-two million, twenty-two thousand, one hundred twenty-one".