Alright, let's work through 63904364 times 10154872 step by step
63904364 × 10154872 = 10154872 × (63904364)
+ 10154872 × 4 which equals 40619488
+ 10154872 × 60 that results in 609292320
+ 10154872 × 300 resulting in 3046461600
+ 10154872 × 4000 that equals 40619488000
+ 10154872 × 00000 which equals 0
+ 10154872 × 900000 that equals 9139384800000
+ 10154872 × 3000000 resulting in 30464616000000
+ 10154872 × 60000000 producing 609292320000000

= 648940636661408
