Detects if given integer is a prime?

is-prime.clj

; Clojure step 1

(defn is-prime? [n]
  "Detects if input paramter is a prime."
  (if (<= n 3)
    true
    (let [max (Math/floor (Math/sqrt n))]
      (loop [d 2]
        (if (zero? (rem n d))
          false
          (if (> d max)
            true
            (recur (inc d))))))))

(defn ARGV [n] (Long. (nth *command-line-args* n)))

(println (is-prime? (ARGV 0)))