Alright, let's work through 4086 times 6784 step by step
4086 × 6784 = 6784 × (4086)
+ 6784 × 6 that is equal 40704
+ 6784 × 80 yielding 542720
+ 6784 × 000 which equals 0
+ 6784 × 4000 yielding 27136000

= 27719424
