18225 has 21 divisors (see below), whose sum is σ = 33883.
Its totient is φ = 9720.
The previous prime is 18223. The next prime is 18229. The reversal of 18225 is 52281.
It can be divided in two parts, 18 and 225, that added together give a 5-th power (243 = 35).
18225 = T25 + T26 + ... +
The square root of 18225 is 135.
It is a perfect power (a square), and thus also a powerful number.
It can be written as a sum of positive squares in only one way, i.e., 6561 + 11664 = 81^2 + 108^2
It is not a de Polignac number, because 18225 - 21 = 18223 is a prime.
It is a Duffinian number.
Its product of digits (160) is a multiple of the sum of its prime divisors (8).
It is a Curzon number.
It is a nialpdrome in base 3.
It is a junction number, because it is equal to n+sod(n) for n = 18198 and 18207.
It is not an unprimeable number, because it can be changed into a prime (18223) 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 20 ways as a sum of consecutive naturals, for example, 3643 + ... + 3647.
18225 is a Friedman number, since it can be written as 225*81, using all its digits and the basic arithmetic operations.
218225 is an apocalyptic number.
18225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.
18225 is the 135-th square number.
18225 is the 68-th centered octagonal number.
It is an amenable number.
18225 is a deficient number, since it is larger than the sum of its proper divisors (15658).
18225 is an frugal number, since it uses more digits than its factorization.
18225 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 28 (or 8 counting only the distinct ones).
The product of its digits is 160, while the sum is 18.
The cubic root of 18225 is about 26.3161596439.
The spelling of 18225 in words is "eighteen thousand, two hundred twenty-five".