Alright, let's work through 3855 times 5407 step by step
3855 × 5407 = 5407 × (3855)
+ 5407 × 5 resulting in 27035
+ 5407 × 50 which equals 270350
+ 5407 × 800 which equals 4325600
+ 5407 × 3000 resulting in 16221000

= 20843985
