Alright, let's work through 52800875 times 80987831 step by step
52800875 × 80987831 = 80987831 × (52800875)
+ 80987831 × 5 that results in 404939155
+ 80987831 × 70 giving us 5669148170
+ 80987831 × 800 what gives us 64790264800
+ 80987831 × 0000 what gives us 0
+ 80987831 × 00000 yielding 0
+ 80987831 × 800000 producing 64790264800000
+ 80987831 × 2000000 what gives us 161975662000000
+ 80987831 × 50000000 resulting in 4049391550000000

= 4276228341152125
