18999 has 6 divisors (see below), whose sum is σ = 27456. Its totient is φ = 12660.

The previous prime is 18979. The next prime is 19001. The reversal of 18999 is 99981.

18999 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 18999 - 2⁸ = 18743 is a prime.

18999 is a modest number, since divided by 999 gives 18 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18919) 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, 1047 + ... + 1064.

It is an arithmetic number, because the mean of its divisors is an integer number (4576).

2¹⁸⁹⁹⁹ is an apocalyptic number.

18999 is a deficient number, since it is larger than the sum of its proper divisors (8457).

18999 is a wasteful number, since it uses less digits than its factorization.

18999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2117 (or 2114 counting only the distinct ones).

The product of its digits is 5832, while the sum is 36.

The square root of 18999 is about 137.8368600919. The cubic root of 18999 is about 26.6835483384.

The spelling of 18999 in words is "eighteen thousand, nine hundred ninety-nine".