12517871521 has 4 divisors (see below), whose sum is σ = 12534540544. Its totient is φ = 12501202500.

The previous prime is 12517871503. The next prime is 12517871537.

12517871521 is nontrivially palindromic in base 10.

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.

It is a cyclic number.

It is not a de Polignac number, because 12517871521 - 2¹⁹ = 12517347233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12517871551) 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 in 3 ways as a sum of consecutive naturals, for example, 8333385 + ... + 8334886.

It is an arithmetic number, because the mean of its divisors is an integer number (3133635136).

Almost surely, 2^12517871521 is an apocalyptic number.

It is an amenable number.

12517871521 is a deficient number, since it is larger than the sum of its proper divisors (16669023).

12517871521 is an equidigital number, since it uses as much as digits as its factorization.

12517871521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16669022.

The product of its digits is 39200, while the sum is 40.

The spelling of 12517871521 in words is "twelve billion, five hundred seventeen million, eight hundred seventy-one thousand, five hundred twenty-one".