Alright, let's work through 81979912 times 11705707 step by step
81979912 × 11705707 = 11705707 × (81979912)
+ 11705707 × 2 yielding 23411414
+ 11705707 × 10 resulting in 117057070
+ 11705707 × 900 that equals 10535136300
+ 11705707 × 9000 yielding 105351363000
+ 11705707 × 70000 giving us 819399490000
+ 11705707 × 900000 resulting in 10535136300000
+ 11705707 × 1000000 producing 11705707000000
+ 11705707 × 80000000 that equals 936456560000000

= 959632829757784
