18005504 has 80 divisors (see below), whose sum is σ = 41247360. Its totient is φ = 7772160.

The previous prime is 18005503. The next prime is 18005509. The reversal of 18005504 is 40550081.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 18005504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18005503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129467 + ... + 129605.

It is an arithmetic number, because the mean of its divisors is an integer number (515592).

Almost surely, 2^18005504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18005504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20623680).

18005504 is an abundant number, since it is smaller than the sum of its proper divisors (23241856).

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

18005504 is a wasteful number, since it uses less digits than its factorization.

18005504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 18005504 is about 4243.2892901616. The cubic root of 18005504 is about 262.1008488480.

Adding to 18005504 its reverse (40550081), we get a palindrome (58555585).

The spelling of 18005504 in words is "eighteen million, five thousand, five hundred four".