Alright, let's work through 6487 times 6639 step by step
6487 × 6639 = 6639 × (6487)
+ 6639 × 7 yielding 46473
+ 6639 × 80 what gives us 531120
+ 6639 × 400 what gives us 2655600
+ 6639 × 6000 that results in 39834000

= 43067193
