/* REXX       FACTORS     Determine factors of a supplied number.

*/ arg argline                         /* pro-forma quick-start      */
address TSO
arg parms "((" opts
opts = Strip(opts,"T",")")
parse var opts "TRACE"  tv  .
parse value tv "N"  with  tv .
rc = Trace("O"); rc = Trace(tv)

parse value "0"  with sum faclist
parse var parms  num  .
do fac = 2 to num                      /*                            */
   if fac**2 >  num then leave         /*                            */
   if num // fac = 0 then do
      hifac = num / fac
      if hifac = fac then do
         hifac = ''
         sum = sum + fac
         end
      else ,
         sum = sum + fac + hifac
      faclist = faclist fac hifac
      end                              /* evenly divisible           */
end                                    /* fac                        */
faclist = STRSORT( faclist )
say "Factors of" num "are" faclist
say "and their sum is" sum

exit                                   /*@ FACTORS                   */