Alright, let's work through 81720607 times 67070979 step by step
81720607 × 67070979 = 67070979 × (81720607)
+ 67070979 × 7 yielding 469496853
+ 67070979 × 00 that equals 0
+ 67070979 × 600 which equals 40242587400
+ 67070979 × 0000 that equals 0
+ 67070979 × 20000 that results in 1341419580000
+ 67070979 × 700000 giving us 46949685300000
+ 67070979 × 1000000 producing 67070979000000
+ 67070979 × 80000000 that is equal 5365678320000000

= 5481081115964253
