Alright, let's work through 68108109 times 99897100 step by step
68108109 × 99897100 = 99897100 × (68108109)
+ 99897100 × 9 yielding 899073900
+ 99897100 × 00 what gives us 0
+ 99897100 × 100 that is equal 9989710000
+ 99897100 × 8000 which equals 799176800000
+ 99897100 × 00000 what gives us 0
+ 99897100 × 100000 which equals 9989710000000
+ 99897100 × 8000000 yielding 799176800000000
+ 99897100 × 60000000 what gives us 5993826000000000

= 6803802575583900
