Alright, let's work through 81844374 times 77684871 step by step
81844374 × 77684871 = 77684871 × (81844374)
+ 77684871 × 4 yielding 310739484
+ 77684871 × 70 giving us 5437940970
+ 77684871 × 300 which equals 23305461300
+ 77684871 × 4000 that results in 310739484000
+ 77684871 × 40000 which equals 3107394840000
+ 77684871 × 800000 producing 62147896800000
+ 77684871 × 1000000 what gives us 77684871000000
+ 77684871 × 80000000 which equals 6214789680000000

= 6358069636265754
