12556431017 has 4 divisors (see below), whose sum is σ = 13522310340. Its totient is φ = 11590551696.

The previous prime is 12556430987. The next prime is 12556431031. The reversal of 12556431017 is 71013465521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7819688041 + 4736742976 = 88429^2 + 68824^2 .

It is a cyclic number.

It is not a de Polignac number, because 12556431017 - 2²² = 12552236713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12556439017) 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, 482939642 + ... + 482939667.

It is an arithmetic number, because the mean of its divisors is an integer number (3380577585).

Almost surely, 2^12556431017 is an apocalyptic number.

It is an amenable number.

12556431017 is a deficient number, since it is larger than the sum of its proper divisors (965879323).

12556431017 is an equidigital number, since it uses as much as digits as its factorization.

12556431017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965879322.

The product of its (nonzero) digits is 25200, while the sum is 35.

Adding to 12556431017 its reverse (71013465521), we get a palindrome (83569896538).

The spelling of 12556431017 in words is "twelve billion, five hundred fifty-six million, four hundred thirty-one thousand, seventeen".