12665839 has 2 divisors, whose sum is σ = 12665840. Its totient is φ = 12665838.

The previous prime is 12665827. The next prime is 12665869. The reversal of 12665839 is 93856621.

It is a weak prime.

It is an emirp because it is prime and its reverse (93856621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12665839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12665869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6332919 + 6332920.

It is an arithmetic number, because the mean of its divisors is an integer number (6332920).

Almost surely, 2^12665839 is an apocalyptic number.

12665839 is a deficient number, since it is larger than the sum of its proper divisors (1).

12665839 is an equidigital number, since it uses as much as digits as its factorization.

12665839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 40.

The square root of 12665839 is about 3558.9098049824. The cubic root of 12665839 is about 233.1012779088.

The spelling of 12665839 in words is "twelve million, six hundred sixty-five thousand, eight hundred thirty-nine".