Alright, let's work through 6391 times 6540 step by step
6391 × 6540 = 6540 × (6391)
+ 6540 × 1 giving us 6540
+ 6540 × 90 producing 588600
+ 6540 × 300 that is equal 1962000
+ 6540 × 6000 giving us 39240000

= 41797140
