12211111121981 has 2 divisors, whose sum is σ = 12211111121982. Its totient is φ = 12211111121980.

The previous prime is 12211111121921. The next prime is 12211111122011. The reversal of 12211111121981 is 18912111111221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9451412719225 + 2759698402756 = 3074315^2 + 1661234^2 .

It is a cyclic number.

It is not a de Polignac number, because 12211111121981 - 2⁴² = 7813064610877 is a prime.

It is a super-2 number, since 2×12211111121981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12211111121921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6105555560990 + 6105555560991.

It is an arithmetic number, because the mean of its divisors is an integer number (6105555560991).

Almost surely, 2^{12211111121981} is an apocalyptic number.

It is an amenable number.

12211111121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12211111121981 is an equidigital number, since it uses as much as digits as its factorization.

12211111121981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 32.

The spelling of 12211111121981 in words is "twelve trillion, two hundred eleven billion, one hundred eleven million, one hundred twenty-one thousand, nine hundred eighty-one".