Alright, let's work through 1689 times 8103 step by step
1689 × 8103 = 8103 × (1689)
+ 8103 × 9 what gives us 72927
+ 8103 × 80 giving us 648240
+ 8103 × 600 producing 4861800
+ 8103 × 1000 resulting in 8103000

= 13685967
