Alright, let's work through 8191 times 9090 step by step
8191 × 9090 = 9090 × (8191)
+ 9090 × 1 what gives us 9090
+ 9090 × 90 that is equal 818100
+ 9090 × 100 that is equal 909000
+ 9090 × 8000 resulting in 72720000

= 74456190
