Alright, let's work through 6403 times 4295 step by step
6403 × 4295 = 4295 × (6403)
+ 4295 × 3 resulting in 12885
+ 4295 × 00 resulting in 0
+ 4295 × 400 producing 1718000
+ 4295 × 6000 which equals 25770000

= 27500885
