Alright, let's work through 99689129 times 78815996 step by step
99689129 × 78815996 = 78815996 × (99689129)
+ 78815996 × 9 which equals 709343964
+ 78815996 × 20 that equals 1576319920
+ 78815996 × 100 what gives us 7881599600
+ 78815996 × 9000 resulting in 709343964000
+ 78815996 × 80000 that equals 6305279680000
+ 78815996 × 600000 that results in 47289597600000
+ 78815996 × 9000000 that equals 709343964000000
+ 78815996 × 90000000 resulting in 7093439640000000

= 7857097992507484
