Alright, let's work through 80399584 times 75113909 step by step
80399584 × 75113909 = 75113909 × (80399584)
+ 75113909 × 4 giving us 300455636
+ 75113909 × 80 giving us 6009112720
+ 75113909 × 500 resulting in 37556954500
+ 75113909 × 9000 that equals 676025181000
+ 75113909 × 90000 giving us 6760251810000
+ 75113909 × 300000 that results in 22534172700000
+ 75113909 × 0000000 that results in 0
+ 75113909 × 80000000 yielding 6009112720000000

= 6039127036213856
