Alright, let's work through 3807 times 4131 step by step
3807 × 4131 = 4131 × (3807)
+ 4131 × 7 giving us 28917
+ 4131 × 00 that results in 0
+ 4131 × 800 producing 3304800
+ 4131 × 3000 that is equal 12393000

= 15726717
