Sum of square and cube digits of an integer are primes

Sum of square and cube digits of an integer are primes is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Task

Sum of square and cube digits of an integer n are primes, where n<100

Ring

<lang ring> load "stdlib.ring" see "working..." +nl

limit = 100

for n = 1 to limit

   sums = 0
   sumc = 0
   sps = string(pow(n,2))
   spc = string(pow(n,3))
   for m = 1 to len(sps)
       sums = sums + sps[m]
   next
   for p = 1 to len(spc)
       sumc = sumc + spc[p]
   next
   if isprime(sums) and isprime(sumc)
      see "" + n + nl
   ok

next

see "done..." + nl </lang>

Output:

working...
16
17
25
28
34
37
47
52
64
done...