18198091 has 2 divisors, whose sum is σ = 18198092. Its totient is φ = 18198090.

The previous prime is 18198053. The next prime is 18198139. The reversal of 18198091 is 19089181.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18198091 - 2⁹ = 18197579 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18198091.

It is not a weakly prime, because it can be changed into another prime (18198001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099045 + 9099046.

It is an arithmetic number, because the mean of its divisors is an integer number (9099046).

Almost surely, 2^18198091 is an apocalyptic number.

18198091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18198091 is an equidigital number, since it uses as much as digits as its factorization.

18198091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 37.

The square root of 18198091 is about 4265.9220574221. The cubic root of 18198091 is about 263.0320142998.

The spelling of 18198091 in words is "eighteen million, one hundred ninety-eight thousand, ninety-one".