divisors :: Integer -> [Integer]
divisors n = nub . concatMap pair . filter f $ [1..(limit n)]
  where pair x = [x, div n x]
        f x = rem n x == 0
        limit = floor . sqrt . (fromIntegral :: Integer -> Double)
divisors :: Integer -> [Integer]
divisors n = nub . concatMap pair . filter f $ [1..(limit n)]
  where pair x = [x, div n x]
        f x = rem n x == 0
        limit = floor . sqrt . (fromIntegral :: Integer -> Double)
divisors n = nub . concatMap pair . filter f $ [1..(limit n)]
  where pair x = [x, div n x]
        f x = rem n x == 0
        limit = floor . sqrt . (fromIntegral :: Integer -> Double)