No problem, we've got 6121 and 3503 to multiply
6121 × 3503 = 3503 × (6121)
+ 3503 × 1 giving us 3503
+ 3503 × 20 yielding 70060
+ 3503 × 100 producing 350300
+ 3503 × 6000 that is equal 21018000

= 21441863
