Is (2⁵⁸+1)/5 an integer? A prime?

(In reply to re: No Subject====error by Ady TZIDON)

You are correct in that I erred in my division.
288230376151711745 / 5 = 57646075230342349
= 107367629 × 536903681
therefore (2⁵⁸+1)/5 is not prime but composite.

All numbers of 2ⁿ + 1 are divisible by 5 where n is a positive integer and  n MOD 4 equals 2.

Edited on April 10, 2007, 8:10 pm

Posted by Dej Mar on 2007-04-10 14:41:42