No problem, we've got 6428 and 2160 to multiply
6428 × 2160 = 2160 × (6428)
+ 2160 × 8 that results in 17280
+ 2160 × 20 that is equal 43200
+ 2160 × 400 that is equal 864000
+ 2160 × 6000 that is equal 12960000

= 13884480
