12031132561 has 4 divisors (see below), whose sum is σ = 13749865792. Its totient is φ = 10312399332.

The previous prime is 12031132517. The next prime is 12031132571. The reversal of 12031132561 is 16523113021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16523113021 = 593 ⋅27863597.

It is a cyclic number.

It is not a de Polignac number, because 12031132561 - 2²⁵ = 11997578129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12031132571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 859366605 + ... + 859366618.

It is an arithmetic number, because the mean of its divisors is an integer number (3437466448).

Almost surely, 2^12031132561 is an apocalyptic number.

It is an amenable number.

12031132561 is a deficient number, since it is larger than the sum of its proper divisors (1718733231).

12031132561 is an equidigital number, since it uses as much as digits as its factorization.

12031132561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718733230.

The product of its (nonzero) digits is 1080, while the sum is 25.

Adding to 12031132561 its reverse (16523113021), we get a palindrome (28554245582).

The spelling of 12031132561 in words is "twelve billion, thirty-one million, one hundred thirty-two thousand, five hundred sixty-one".