Alright, let's work through 80195864 times 12364071 step by step
80195864 × 12364071 = 12364071 × (80195864)
+ 12364071 × 4 yielding 49456284
+ 12364071 × 60 that equals 741844260
+ 12364071 × 800 resulting in 9891256800
+ 12364071 × 5000 what gives us 61820355000
+ 12364071 × 90000 producing 1112766390000
+ 12364071 × 100000 producing 1236407100000
+ 12364071 × 0000000 what gives us 0
+ 12364071 × 80000000 that equals 989125680000000

= 991547356402344
