Alright, let's work through 18487687 times 789997 step by step
18487687 × 789997 = 789997 × (18487687)
+ 789997 × 7 giving us 5529979
+ 789997 × 80 giving us 63199760
+ 789997 × 600 which equals 473998200
+ 789997 × 7000 yielding 5529979000
+ 789997 × 80000 resulting in 63199760000
+ 789997 × 400000 that equals 315998800000
+ 789997 × 8000000 that equals 6319976000000
+ 789997 × 10000000 resulting in 7899970000000

= 14605217266939
