returns true if the integer is prime and a palindrome

palindromePrime.hs

divides d n = rem n d == 0

ldf k n | divides k n   = k
        | k^2 > n       = n
        | otherwise = ldf (k+1) n

ld n = ldf 2 n

prime0 n | n < 1 = error "not a positive integer"
        | n == 1 = False
        | otherwise = ld n == n

pp n   = (show n == reverse (show n) ) && prime0 n