12331121981 has 2 divisors, whose sum is σ = 12331121982. Its totient is φ = 12331121980.

The previous prime is 12331121941. The next prime is 12331122007. The reversal of 12331121981 is 18912113321.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7665002500 + 4666119481 = 87550^2 + 68309^2 .

It is a cyclic number.

It is not a de Polignac number, because 12331121981 - 2²⁶ = 12264013117 is a prime.

It is a super-2 number, since 2×12331121981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12331121941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6165560990 + 6165560991.

It is an arithmetic number, because the mean of its divisors is an integer number (6165560991).

Almost surely, 2^12331121981 is an apocalyptic number.

It is an amenable number.

12331121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12331121981 is an equidigital number, since it uses as much as digits as its factorization.

12331121981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 32.

The spelling of 12331121981 in words is "twelve billion, three hundred thirty-one million, one hundred twenty-one thousand, nine hundred eighty-one".