21122111211121 has 2 divisors, whose sum is σ = 21122111211122. Its totient is φ = 21122111211120.

The previous prime is 21122111210999. The next prime is 21122111211143. The reversal of 21122111211121 is 12111211122112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20718519097600 + 403592113521 = 4551760^2 + 635289^2 .

It is a cyclic number.

It is not a de Polignac number, because 21122111211121 - 2²⁷ = 21121976993393 is a prime.

It is a super-2 number, since 2×21122111211121² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21122111211191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561055605560 + 10561055605561.

It is an arithmetic number, because the mean of its divisors is an integer number (10561055605561).

Almost surely, 2^{21122111211121} is an apocalyptic number.

It is an amenable number.

21122111211121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122111211121 is an equidigital number, since it uses as much as digits as its factorization.

21122111211121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 19.

Adding to 21122111211121 its reverse (12111211122112), we get a palindrome (33233322333233).

The spelling of 21122111211121 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred eleven million, two hundred eleven thousand, one hundred twenty-one".