12391523 has 4 divisors (see below), whose sum is σ = 12400080. Its totient is φ = 12382968.

The previous prime is 12391501. The next prime is 12391541. The reversal of 12391523 is 32519321.

12391523 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 32519321 = 67 ⋅485363.

It is a cyclic number.

It is not a de Polignac number, because 12391523 - 2¹⁸ = 12129379 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12391492 and 12391501.

It is not an unprimeable number, because it can be changed into a prime (12391543) 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, 1508 + ... + 5201.

It is an arithmetic number, because the mean of its divisors is an integer number (3100020).

Almost surely, 2^12391523 is an apocalyptic number.

12391523 is a deficient number, since it is larger than the sum of its proper divisors (8557).

12391523 is an equidigital number, since it uses as much as digits as its factorization.

12391523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8556.

The product of its digits is 1620, while the sum is 26.

The square root of 12391523 is about 3520.1595134312. The cubic root of 12391523 is about 231.4061494197.

The spelling of 12391523 in words is "twelve million, three hundred ninety-one thousand, five hundred twenty-three".