18387 has 10 divisors (see below), whose sum is σ = 27588.
Its totient is φ = 12204.
The previous prime is 18379. The next prime is 18397. The reversal of 18387 is 78381.
It is not a de Polignac number, because 18387 - 23 = 18379 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (27).
It is an alternating number because its digits alternate between odd and even.
It is a plaindrome in base 15.
It is a self number, because there is not a number n which added to its sum of digits gives 18387.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 18387.
It is not an unprimeable number, because it can be changed into a prime (18307) by changing a digit.
It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 33 + ... + 194.
218387 is an apocalyptic number.
18387 is a deficient number, since it is larger than the sum of its proper divisors (9201).
18387 is an equidigital number, since it uses as much as digits as its factorization.
18387 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 239 (or 230 counting only the distinct ones).
The product of its digits is 1344, while the sum is 27.
The square root of 18387 is about 135.5986725599.
The cubic root of 18387 is about 26.3939035510.
The spelling of 18387 in words is "eighteen thousand, three hundred eighty-seven".