22111212121 has 2 divisors, whose sum is σ = 22111212122. Its totient is φ = 22111212120.

The previous prime is 22111212103. The next prime is 22111212131. The reversal of 22111212121 is 12121211122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20633886025 + 1477326096 = 143645^2 + 38436^2 .

It is a cyclic number.

It is not a de Polignac number, because 22111212121 - 2⁵ = 22111212089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22111212095 and 22111212104.

It is not a weakly prime, because it can be changed into another prime (22111212131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11055606060 + 11055606061.

It is an arithmetic number, because the mean of its divisors is an integer number (11055606061).

Almost surely, 2^22111212121 is an apocalyptic number.

It is an amenable number.

22111212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

22111212121 is an equidigital number, since it uses as much as digits as its factorization.

22111212121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 16.

Adding to 22111212121 its reverse (12121211122), we get a palindrome (34232423243).

Subtracting from 22111212121 its reverse (12121211122), we obtain a palindrome (9990000999).

The spelling of 22111212121 in words is "twenty-two billion, one hundred eleven million, two hundred twelve thousand, one hundred twenty-one".