No problem, we've got 4689 and 8400 to multiply
4689 × 8400 = 8400 × (4689)
+ 8400 × 9 that is equal 75600
+ 8400 × 80 that results in 672000
+ 8400 × 600 which equals 5040000
+ 8400 × 4000 producing 33600000

= 39387600
