No problem, we've got 5428 and 6640 to multiply
5428 × 6640 = 6640 × (5428)
+ 6640 × 8 resulting in 53120
+ 6640 × 20 yielding 132800
+ 6640 × 400 that results in 2656000
+ 6640 × 5000 yielding 33200000

= 36041920
