Which of the numbers below is a divisor of 59048 (= 310 - 1)?
62
242
123
No, 62 = 2 × 31, and the latter prime does not divide
59048.
Right. 242 = 35 - 1 divides 310 - 1 by the lemma.
No, 123 = 3 × 41, and the latter prime does not divide
59048.