Alright, let's work through 6659 times 6039 step by step
6659 × 6039 = 6039 × (6659)
+ 6039 × 9 which equals 54351
+ 6039 × 50 that equals 301950
+ 6039 × 600 that equals 3623400
+ 6039 × 6000 that results in 36234000

= 40213701
