12543549791 has 4 divisors (see below), whose sum is σ = 12558718152. Its totient is φ = 12528381432.

The previous prime is 12543549779. The next prime is 12543549793. The reversal of 12543549791 is 19794534521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19794534521 = 12899 ⋅1534579.

It is a cyclic number.

It is not a de Polignac number, because 12543549791 - 2³⁰ = 11469807967 is a prime.

It is a super-2 number, since 2×12543549791² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12543549793) 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, 7582940 + ... + 7584593.

It is an arithmetic number, because the mean of its divisors is an integer number (3139679538).

Almost surely, 2^12543549791 is an apocalyptic number.

12543549791 is a deficient number, since it is larger than the sum of its proper divisors (15168361).

12543549791 is an equidigital number, since it uses as much as digits as its factorization.

12543549791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15168360.

The product of its digits is 1360800, while the sum is 50.

The spelling of 12543549791 in words is "twelve billion, five hundred forty-three million, five hundred forty-nine thousand, seven hundred ninety-one".