No problem, we've got 1639 and 9235 to multiply
1639 × 9235 = 9235 × (1639)
+ 9235 × 9 what gives us 83115
+ 9235 × 30 yielding 277050
+ 9235 × 600 which equals 5541000
+ 9235 × 1000 resulting in 9235000

= 15136165
