12131221031 has 2 divisors, whose sum is σ = 12131221032. Its totient is φ = 12131221030.

The previous prime is 12131221019. The next prime is 12131221051. The reversal of 12131221031 is 13012213121.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12131221031 is a prime.

It is a super-2 number, since 2×12131221031² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12131221051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6065610515 + 6065610516.

It is an arithmetic number, because the mean of its divisors is an integer number (6065610516).

Almost surely, 2^12131221031 is an apocalyptic number.

12131221031 is a deficient number, since it is larger than the sum of its proper divisors (1).

12131221031 is an equidigital number, since it uses as much as digits as its factorization.

12131221031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 12131221031 its reverse (13012213121), we get a palindrome (25143434152).

The spelling of 12131221031 in words is "twelve billion, one hundred thirty-one million, two hundred twenty-one thousand, thirty-one".