12523606561 has 4 divisors (see below), whose sum is σ = 12862082452. Its totient is φ = 12185130672.

The previous prime is 12523606523. The next prime is 12523606573. The reversal of 12523606561 is 16560632521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16560632521 = 108041 ⋅153281.

It can be written as a sum of positive squares in 2 ways, for example, as 12148448400 + 375158161 = 110220^2 + 19369^2 .

It is not a de Polignac number, because 12523606561 - 2⁹ = 12523606049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 338475853 = 12523606561 / (1 + 2 + 5 + 2 + 3 + 6 + 0 + 6 + 5 + 6 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12523606561.

It is not an unprimeable number, because it can be changed into a prime (12523607561) 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, 169237890 + ... + 169237963.

It is an arithmetic number, because the mean of its divisors is an integer number (3215520613).

Almost surely, 2^12523606561 is an apocalyptic number.

It is an amenable number.

12523606561 is a deficient number, since it is larger than the sum of its proper divisors (338475891).

12523606561 is an equidigital number, since it uses as much as digits as its factorization.

12523606561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338475890.

The product of its (nonzero) digits is 64800, while the sum is 37.

The spelling of 12523606561 in words is "twelve billion, five hundred twenty-three million, six hundred six thousand, five hundred sixty-one".