18169091 has 4 divisors (see below), whose sum is σ = 18591672. Its totient is φ = 17746512.

The previous prime is 18169061. The next prime is 18169093. The reversal of 18169091 is 19096181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18169091 - 2¹⁸ = 17906947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18169093) 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 in 3 ways as a sum of consecutive naturals, for example, 211226 + ... + 211311.

It is an arithmetic number, because the mean of its divisors is an integer number (4647918).

Almost surely, 2^18169091 is an apocalyptic number.

18169091 is a deficient number, since it is larger than the sum of its proper divisors (422581).

18169091 is an equidigital number, since it uses as much as digits as its factorization.

18169091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422580.

The product of its (nonzero) digits is 3888, while the sum is 35.

The square root of 18169091 is about 4262.5216714992. The cubic root of 18169091 is about 262.8922197119.

The spelling of 18169091 in words is "eighteen million, one hundred sixty-nine thousand, ninety-one".