No problem, we've got 6439 and 4355 to multiply
6439 × 4355 = 4355 × (6439)
+ 4355 × 9 that results in 39195
+ 4355 × 30 which equals 130650
+ 4355 × 400 what gives us 1742000
+ 4355 × 6000 yielding 26130000

= 28041845
