Alright, let's work through 12748857 times 18728125 step by step
12748857 × 18728125 = 18728125 × (12748857)
+ 18728125 × 7 which equals 131096875
+ 18728125 × 50 that results in 936406250
+ 18728125 × 800 resulting in 14982500000
+ 18728125 × 8000 giving us 149825000000
+ 18728125 × 40000 that results in 749125000000
+ 18728125 × 700000 producing 13109687500000
+ 18728125 × 2000000 producing 37456250000000
+ 18728125 × 10000000 yielding 187281250000000

= 238762187503125
