Alright, let's work through 6466120 times 51257913 step by step
6466120 × 51257913 = 51257913 × (6466120)
+ 51257913 × 0 that equals 0
+ 51257913 × 20 which equals 1025158260
+ 51257913 × 100 which equals 5125791300
+ 51257913 × 6000 that is equal 307547478000
+ 51257913 × 60000 resulting in 3075474780000
+ 51257913 × 400000 yielding 20503165200000
+ 51257913 × 6000000 producing 307547478000000

= 331439816407560
