12391543 has 2 divisors, whose sum is σ = 12391544. Its totient is φ = 12391542.

The previous prime is 12391541. The next prime is 12391571. The reversal of 12391543 is 34519321.

It is an a-pointer prime, because the next prime (12391571) can be obtained adding 12391543 to its sum of digits (28).

It is a weak prime.

It is an emirp because it is prime and its reverse (34519321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12391543 - 2¹ = 12391541 is a prime.

Together with 12391541, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12391541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6195771 + 6195772.

It is an arithmetic number, because the mean of its divisors is an integer number (6195772).

Almost surely, 2^12391543 is an apocalyptic number.

12391543 is a deficient number, since it is larger than the sum of its proper divisors (1).

12391543 is an equidigital number, since it uses as much as digits as its factorization.

12391543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 28.

The square root of 12391543 is about 3520.1623542104. The cubic root of 12391543 is about 231.4062739167.

The spelling of 12391543 in words is "twelve million, three hundred ninety-one thousand, five hundred forty-three".