12331661581 has 2 divisors, whose sum is σ = 12331661582. Its totient is φ = 12331661580.

The previous prime is 12331661429. The next prime is 12331661627. The reversal of 12331661581 is 18516613321.

12331661581 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., 11986965225 + 344696356 = 109485^2 + 18566^2 .

It is a cyclic number.

It is not a de Polignac number, because 12331661581 - 2¹⁷ = 12331530509 is a prime.

It is a super-2 number, since 2×12331661581² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12331661581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12331661981) 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, 6165830790 + 6165830791.

It is an arithmetic number, because the mean of its divisors is an integer number (6165830791).

Almost surely, 2^12331661581 is an apocalyptic number.

It is an amenable number.

12331661581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12331661581 is an equidigital number, since it uses as much as digits as its factorization.

12331661581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The spelling of 12331661581 in words is "twelve billion, three hundred thirty-one million, six hundred sixty-one thousand, five hundred eighty-one".