Alright, let's work through 8191 times 1564 step by step
8191 × 1564 = 1564 × (8191)
+ 1564 × 1 that results in 1564
+ 1564 × 90 that is equal 140760
+ 1564 × 100 which equals 156400
+ 1564 × 8000 that is equal 12512000

= 12810724
