18118809 has 24 divisors (see below), whose sum is σ = 27361152. Its totient is φ = 11981520.

The previous prime is 18118801. The next prime is 18118811. The reversal of 18118809 is 90881181.

It is not a de Polignac number, because 18118809 - 2³ = 18118801 is a prime.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (18118801) 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 23 ways as a sum of consecutive naturals, for example, 41824 + ... + 42254.

It is an arithmetic number, because the mean of its divisors is an integer number (1140048).

Almost surely, 2^18118809 is an apocalyptic number.

It is an amenable number.

18118809 is a deficient number, since it is larger than the sum of its proper divisors (9242343).

18118809 is an equidigital number, since it uses as much as digits as its factorization.

18118809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 18118809 is about 4256.6194333062. The cubic root of 18118809 is about 262.6494822072.

The spelling of 18118809 in words is "eighteen million, one hundred eighteen thousand, eight hundred nine".