Alright, let's work through 3648 times 1680 step by step
3648 × 1680 = 1680 × (3648)
+ 1680 × 8 that results in 13440
+ 1680 × 40 yielding 67200
+ 1680 × 600 that is equal 1008000
+ 1680 × 3000 resulting in 5040000

= 6128640
