18821811187 has 2 divisors, whose sum is σ = 18821811188. Its totient is φ = 18821811186.

The previous prime is 18821811181. The next prime is 18821811199. The reversal of 18821811187 is 78111812881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18821811187 - 2¹⁵ = 18821778419 is a prime.

It is not a weakly prime, because it can be changed into another prime (18821811181) 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, 9410905593 + 9410905594.

It is an arithmetic number, because the mean of its divisors is an integer number (9410905594).

Almost surely, 2^18821811187 is an apocalyptic number.

18821811187 is a deficient number, since it is larger than the sum of its proper divisors (1).

18821811187 is an equidigital number, since it uses as much as digits as its factorization.

18821811187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57344, while the sum is 46.

The spelling of 18821811187 in words is "eighteen billion, eight hundred twenty-one million, eight hundred eleven thousand, one hundred eighty-seven".