12534817681 has 3 divisors (see below), whose sum is σ = 12534929641. Its totient is φ = 12534705722.

The previous prime is 12534817651. The next prime is 12534817739. The reversal of 12534817681 is 18671843521.

The square root of 12534817681 is 111959.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18671843521 = 5179 ⋅3605299.

It is not a de Polignac number, because 12534817681 - 2⁵ = 12534817649 is a prime.

It is a super-2 number, since 2×12534817681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12534817601) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 55980 + ... + 167938.

Almost surely, 2^12534817681 is an apocalyptic number.

12534817681 is the 111959-th square number.

12534817681 is the 55980-th centered octagonal number.

It is an amenable number.

12534817681 is a deficient number, since it is larger than the sum of its proper divisors (111960).

12534817681 is an frugal number, since it uses more digits than its factorization.

12534817681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223918 (or 111959 counting only the distinct ones).

The product of its digits is 322560, while the sum is 46.

The spelling of 12534817681 in words is "twelve billion, five hundred thirty-four million, eight hundred seventeen thousand, six hundred eighty-one".