18117191 has 2 divisors, whose sum is σ = 18117192. Its totient is φ = 18117190.

The previous prime is 18117179. The next prime is 18117227. The reversal of 18117191 is 19171181.

It is a weak prime.

It is an emirp because it is prime and its reverse (19171181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18117191 - 2¹⁰ = 18116167 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 18117191 parts by 6019 straight cuts.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18117101) 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, 9058595 + 9058596.

It is an arithmetic number, because the mean of its divisors is an integer number (9058596).

Almost surely, 2^18117191 is an apocalyptic number.

18117191 is a deficient number, since it is larger than the sum of its proper divisors (1).

18117191 is an equidigital number, since it uses as much as digits as its factorization.

18117191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 29.

The square root of 18117191 is about 4256.4293721381. The cubic root of 18117191 is about 262.6416638215.

The spelling of 18117191 in words is "eighteen million, one hundred seventeen thousand, one hundred ninety-one".