Alright, let's work through 87893814 times 78623821 step by step
87893814 × 78623821 = 78623821 × (87893814)
+ 78623821 × 4 that is equal 314495284
+ 78623821 × 10 which equals 786238210
+ 78623821 × 800 that results in 62899056800
+ 78623821 × 3000 resulting in 235871463000
+ 78623821 × 90000 what gives us 7076143890000
+ 78623821 × 800000 what gives us 62899056800000
+ 78623821 × 7000000 that results in 550366747000000
+ 78623821 × 80000000 producing 6289905680000000

= 6910547498943294
