Alright, let's work through 79720006 times 81493500 step by step
79720006 × 81493500 = 81493500 × (79720006)
+ 81493500 × 6 producing 488961000
+ 81493500 × 00 producing 0
+ 81493500 × 000 resulting in 0
+ 81493500 × 0000 yielding 0
+ 81493500 × 20000 yielding 1629870000000
+ 81493500 × 700000 which equals 57045450000000
+ 81493500 × 9000000 resulting in 733441500000000
+ 81493500 × 70000000 yielding 5704545000000000

= 6496662308961000
