12111121021 has 2 divisors, whose sum is σ = 12111121022. Its totient is φ = 12111121020.

The previous prime is 12111121007. The next prime is 12111121031. The reversal of 12111121021 is 12012111121.

It is a happy number.

12111121021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10319715396 + 1791405625 = 101586^2 + 42325^2 .

It is an emirp because it is prime and its reverse (12012111121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12111121021 - 2¹⁹ = 12110596733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12111120992 and 12111121010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12111121031) 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, 6055560510 + 6055560511.

It is an arithmetic number, because the mean of its divisors is an integer number (6055560511).

Almost surely, 2^12111121021 is an apocalyptic number.

It is an amenable number.

12111121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12111121021 is an equidigital number, since it uses as much as digits as its factorization.

12111121021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 12111121021 its reverse (12012111121), we get a palindrome (24123232142).

The spelling of 12111121021 in words is "twelve billion, one hundred eleven million, one hundred twenty-one thousand, twenty-one".