18004 has 12 divisors (see below), whose sum is σ = 36064. Its totient is φ = 7704.

The previous prime is 17989. The next prime is 18013. The reversal of 18004 is 40081.

18004 = 15² + 16² + ... + 38².

18004 is an admirable number.

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 294 + ... + 349.

2¹⁸⁰⁰⁴ is an apocalyptic number.

18004 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18004 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18032).

18004 is a wasteful number, since it uses less digits than its factorization.

18004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 654 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 18004 is about 134.1789849418. The cubic root of 18004 is about 26.2093550882.

Adding to 18004 its reverse (40081), we get a palindrome (58085).

The spelling of 18004 in words is "eighteen thousand, four".