Alright, let's work through 6401 times 1973 step by step
6401 × 1973 = 1973 × (6401)
+ 1973 × 1 producing 1973
+ 1973 × 00 yielding 0
+ 1973 × 400 resulting in 789200
+ 1973 × 6000 giving us 11838000

= 12629173
