18663 has 4 divisors (see below), whose sum is σ = 24888. Its totient is φ = 12440.

The previous prime is 18661. The next prime is 18671. The reversal of 18663 is 36681.

18663 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36681 = 3 ⋅12227.

It is a cyclic number.

It is not a de Polignac number, because 18663 - 2¹ = 18661 is a prime.

It is a D-number.

It is a plaindrome in base 6.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18661) 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, 3108 + ... + 3113.

It is an arithmetic number, because the mean of its divisors is an integer number (6222).

2¹⁸⁶⁶³ is an apocalyptic number.

18663 is a deficient number, since it is larger than the sum of its proper divisors (6225).

18663 is an equidigital number, since it uses as much as digits as its factorization.

18663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6224.

The product of its digits is 864, while the sum is 24.

The square root of 18663 is about 136.6125909278. The cubic root of 18663 is about 26.5253110489.

The spelling of 18663 in words is "eighteen thousand, six hundred sixty-three".