18119890891 has 2 divisors, whose sum is σ = 18119890892. Its totient is φ = 18119890890.

The previous prime is 18119890819. The next prime is 18119890907. The reversal of 18119890891 is 19809891181.

Together with previous prime (18119890819) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18119890891 - 2¹⁵ = 18119858123 is a prime.

It is not a weakly prime, because it can be changed into another prime (18119890391) 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, 9059945445 + 9059945446.

It is an arithmetic number, because the mean of its divisors is an integer number (9059945446).

Almost surely, 2^18119890891 is an apocalyptic number.

18119890891 is a deficient number, since it is larger than the sum of its proper divisors (1).

18119890891 is an equidigital number, since it uses as much as digits as its factorization.

18119890891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 55.

The spelling of 18119890891 in words is "eighteen billion, one hundred nineteen million, eight hundred ninety thousand, eight hundred ninety-one".