12181565867 has 2 divisors, whose sum is σ = 12181565868. Its totient is φ = 12181565866.

The previous prime is 12181565857. The next prime is 12181565941. The reversal of 12181565867 is 76856518121.

It is a weak prime.

It is an emirp because it is prime and its reverse (76856518121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12181565867 - 2¹² = 12181561771 is a prime.

It is not a weakly prime, because it can be changed into another prime (12181565827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6090782933 + 6090782934.

It is an arithmetic number, because the mean of its divisors is an integer number (6090782934).

Almost surely, 2^12181565867 is an apocalyptic number.

12181565867 is a deficient number, since it is larger than the sum of its proper divisors (1).

12181565867 is an equidigital number, since it uses as much as digits as its factorization.

12181565867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 806400, while the sum is 50.

The spelling of 12181565867 in words is "twelve billion, one hundred eighty-one million, five hundred sixty-five thousand, eight hundred sixty-seven".