12187878809 has 2 divisors, whose sum is σ = 12187878810. Its totient is φ = 12187878808.

The previous prime is 12187878737. The next prime is 12187878841. The reversal of 12187878809 is 90887878121.

12187878809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10471019584 + 1716859225 = 102328^2 + 41435^2 .

It is an emirp because it is prime and its reverse (90887878121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12187878809 - 2³² = 7892911513 is a prime.

It is not a weakly prime, because it can be changed into another prime (12187875809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6093939404 + 6093939405.

It is an arithmetic number, because the mean of its divisors is an integer number (6093939405).

Almost surely, 2^12187878809 is an apocalyptic number.

It is an amenable number.

12187878809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12187878809 is an equidigital number, since it uses as much as digits as its factorization.

12187878809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3612672, while the sum is 59.

The spelling of 12187878809 in words is "twelve billion, one hundred eighty-seven million, eight hundred seventy-eight thousand, eight hundred nine".