18618 has 16 divisors (see below), whose sum is σ = 38880.
Its totient is φ = 5936.
The previous prime is 18617. The next prime is 18637. The reversal of 18618 is 81681.
It can be divided in two parts, 18 and 618, that added together give a palindrome (636).
It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
It is an Ulam number.
It is a nialpdrome in base 6 and base 13.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (18617) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121 + ... + 227.
It is an arithmetic number, because the mean of its divisors is an integer number (2430).
218618 is an apocalyptic number.
18618 is an abundant number, since it is smaller than the sum of its proper divisors (20262).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19440).
18618 is a wasteful number, since it uses less digits than its factorization.
18618 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 141.
The product of its digits is 384, while the sum is 24.
The square root of 18618 is about 136.4477922137.
The cubic root of 18618 is about 26.5039747212.
The spelling of 18618 in words is "eighteen thousand, six hundred eighteen".