Alright, let's work through 76886907 times 80405817 step by step
76886907 × 80405817 = 80405817 × (76886907)
+ 80405817 × 7 which equals 562840719
+ 80405817 × 00 producing 0
+ 80405817 × 900 producing 72365235300
+ 80405817 × 6000 resulting in 482434902000
+ 80405817 × 80000 that equals 6432465360000
+ 80405817 × 800000 which equals 64324653600000
+ 80405817 × 6000000 resulting in 482434902000000
+ 80405817 × 70000000 producing 5628407190000000

= 6182154573938019
