18098891 has 2 divisors, whose sum is σ = 18098892. Its totient is φ = 18098890.

The previous prime is 18098879. The next prime is 18098909. The reversal of 18098891 is 19889081.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (19889081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18098891 - 2⁶ = 18098827 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18098831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9049445 + 9049446.

It is an arithmetic number, because the mean of its divisors is an integer number (9049446).

Almost surely, 2^18098891 is an apocalyptic number.

18098891 is a deficient number, since it is larger than the sum of its proper divisors (1).

18098891 is an equidigital number, since it uses as much as digits as its factorization.

18098891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18098891 is about 4254.2791398779. The cubic root of 18098891 is about 262.5532034261.

The spelling of 18098891 in words is "eighteen million, ninety-eight thousand, eight hundred ninety-one".