Alright, let's work through 18871165 times 64503392 step by step
18871165 × 64503392 = 64503392 × (18871165)
+ 64503392 × 5 resulting in 322516960
+ 64503392 × 60 that is equal 3870203520
+ 64503392 × 100 yielding 6450339200
+ 64503392 × 1000 that is equal 64503392000
+ 64503392 × 70000 yielding 4515237440000
+ 64503392 × 800000 giving us 51602713600000
+ 64503392 × 8000000 yielding 516027136000000
+ 64503392 × 10000000 that results in 645033920000000

= 1217254153491680
