Alright, let's work through 3891 times 4296 step by step
3891 × 4296 = 4296 × (3891)
+ 4296 × 1 which equals 4296
+ 4296 × 90 yielding 386640
+ 4296 × 800 that is equal 3436800
+ 4296 × 3000 resulting in 12888000

= 16715736
