No problem, we've got 4223 and 864 to multiply
4223 × 864 = 864 × (4223)
+ 864 × 3 that is equal 2592
+ 864 × 20 resulting in 17280
+ 864 × 200 giving us 172800
+ 864 × 4000 that is equal 3456000

= 3648672
