676 : 2 = 338
338 : 2 = 169
169 : 13 = 13
13 : 13 = 1
676 = 2 x 2 x 13 x 13
676 = 2² x 13 x 13
676 = 2^2 × 13^2
676 = 2 × 2 × 13 × 13