No problem, we've got 3840 and 5428 to multiply
3840 × 5428 = 5428 × (3840)
+ 5428 × 0 producing 0
+ 5428 × 40 giving us 217120
+ 5428 × 800 which equals 4342400
+ 5428 × 3000 that results in 16284000

= 20843520
