18918 has 12 divisors (see below), whose sum is σ = 41028.
Its totient is φ = 6300.
The previous prime is 18917. The next prime is 18919. The reversal of 18918 is 81981.
It is an interprime number because it is at equal distance from previous prime (18917) and next prime (18919).
It is an Ulam number.
It is a junction number, because it is equal to n+sod(n) for n = 18891 and 18900.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (18911) by changing a digit.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 508 + ... + 543.
It is an arithmetic number, because the mean of its divisors is an integer number (3419).
218918 is an apocalyptic number.
18918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.
18918 is an abundant number, since it is smaller than the sum of its proper divisors (22110).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18918 is a wasteful number, since it uses less digits than its factorization.
18918 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1059 (or 1056 counting only the distinct ones).
The product of its digits is 576, while the sum is 27.
The square root of 18918 is about 137.5427206362.
The cubic root of 18918 is about 26.6455735978.
The spelling of 18918 in words is "eighteen thousand, nine hundred eighteen".