No problem, we've got 4320 and 6399 to multiply
4320 × 6399 = 6399 × (4320)
+ 6399 × 0 producing 0
+ 6399 × 20 producing 127980
+ 6399 × 300 yielding 1919700
+ 6399 × 4000 producing 25596000

= 27643680
