12121111019981 has 2 divisors, whose sum is σ = 12121111019982. Its totient is φ = 12121111019980.

The previous prime is 12121111019957. The next prime is 12121111020017. The reversal of 12121111019981 is 18991011112121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9707841979081 + 2413269040900 = 3115741^2 + 1553470^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121111019981 - 2²² = 12121106825677 is a prime.

It is a super-2 number, since 2×12121111019981² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12121111019581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6060555509990 + 6060555509991.

It is an arithmetic number, because the mean of its divisors is an integer number (6060555509991).

Almost surely, 2^{12121111019981} is an apocalyptic number.

It is an amenable number.

12121111019981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12121111019981 is an equidigital number, since it uses as much as digits as its factorization.

12121111019981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 38.

The spelling of 12121111019981 in words is "twelve trillion, one hundred twenty-one billion, one hundred eleven million, nineteen thousand, nine hundred eighty-one".