What is the greatest prime factor of 5^6 - 1? Choose the correct option:
A) 29
B) 31
C) 37
D) 41
E) 43
5^6-1 = (5^3-1)(5^3+1) = 124*126 = 4*31*3*42   The answer is 31.
<result>B</result>
What is the greatest prime factor of 5^6 - 1?