Alright, let's work through 78984351 times 65834870 step by step
78984351 × 65834870 = 65834870 × (78984351)
+ 65834870 × 1 yielding 65834870
+ 65834870 × 50 producing 3291743500
+ 65834870 × 300 producing 19750461000
+ 65834870 × 4000 that equals 263339480000
+ 65834870 × 80000 which equals 5266789600000
+ 65834870 × 900000 that equals 59251383000000
+ 65834870 × 8000000 that results in 526678960000000
+ 65834870 × 70000000 resulting in 4608440900000000

= 5199924480119370
