18393 has 4 divisors (see below), whose sum is σ = 24528.
Its totient is φ = 12260.
The previous prime is 18379. The next prime is 18397. The reversal of 18393 is 39381.
It can be divided in two parts, 183 and 93, that added together give a triangular number (276 = T23).
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39381 = 3 ⋅13127.
It is a cyclic number.
It is not a de Polignac number, because 18393 - 26 = 18329 is a prime.
It is a super-3 number, since 3×183933 = 18667190833371, which contains 333 as substring.
It is a D-number.
It is a Curzon number.
It is a plaindrome in base 14.
It is not an unprimeable number, because it can be changed into a prime (18397) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3063 + ... + 3068.
It is an arithmetic number, because the mean of its divisors is an integer number (6132).
218393 is an apocalyptic number.
It is an amenable number.
18393 is a deficient number, since it is larger than the sum of its proper divisors (6135).
18393 is an equidigital number, since it uses as much as digits as its factorization.
18393 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 6134.
The product of its digits is 648, while the sum is 24.
The square root of 18393 is about 135.6207948657.
The cubic root of 18393 is about 26.3967741697.
The spelling of 18393 in words is "eighteen thousand, three hundred ninety-three".