Alright, let's work through 64043309 times 63428539 step by step
64043309 × 63428539 = 63428539 × (64043309)
+ 63428539 × 9 what gives us 570856851
+ 63428539 × 00 that equals 0
+ 63428539 × 300 producing 19028561700
+ 63428539 × 3000 giving us 190285617000
+ 63428539 × 40000 that results in 2537141560000
+ 63428539 × 000000 what gives us 0
+ 63428539 × 4000000 producing 253714156000000
+ 63428539 × 60000000 producing 3805712340000000

= 4062173522595551
