18804 has 12 divisors (see below), whose sum is σ = 43904.
Its totient is φ = 6264.
The previous prime is 18803. The next prime is 18839. The reversal of 18804 is 40881.
Added to its reverse (40881) it gives a triangular number (59685 = T345).
It is a tau number, because it is divible by the number of its divisors (12).
It is a plaindrome in base 15.
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 (18803) 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, 772 + ... + 795.
218804 is an apocalyptic number.
It is an amenable number.
18804 is an abundant number, since it is smaller than the sum of its proper divisors (25100).
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 (21952).
18804 is a wasteful number, since it uses less digits than its factorization.
18804 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1574 (or 1572 counting only the distinct ones).
The product of its (nonzero) digits is 256, while the sum is 21.
The square root of 18804 is about 137.1276777314.
The cubic root of 18804 is about 26.5919435907.
Adding to 18804 its reverse (40881), we get a triangular number (59685 = T345).
The spelling of 18804 in words is "eighteen thousand, eight hundred four".