18789 has 4 divisors (see below), whose sum is σ = 25056. Its totient is φ = 12524.

The previous prime is 18787. The next prime is 18793. The reversal of 18789 is 98781.

18789 is nontrivially palindromic in base 11.

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.

It is a cyclic number.

It is not a de Polignac number, because 18789 - 2¹ = 18787 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between odd and even.

18789 is an undulating number in base 11.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18787) 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 3 ways as a sum of consecutive naturals, for example, 3129 + ... + 3134.

It is an arithmetic number, because the mean of its divisors is an integer number (6264).

2¹⁸⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

18789 is a deficient number, since it is larger than the sum of its proper divisors (6267).

18789 is an equidigital number, since it uses as much as digits as its factorization.

18789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6266.

The product of its digits is 4032, while the sum is 33.

The square root of 18789 is about 137.0729732661. The cubic root of 18789 is about 26.5848708887.

It can be divided in two parts, 187 and 89, that added together give a triangular number (276 = T₂₃).

The spelling of 18789 in words is "eighteen thousand, seven hundred eighty-nine".