Alright, let's work through 6447 times 4092 step by step
6447 × 4092 = 4092 × (6447)
+ 4092 × 7 that results in 28644
+ 4092 × 40 producing 163680
+ 4092 × 400 giving us 1636800
+ 4092 × 6000 what gives us 24552000

= 26381124
