Alright, let's work through 81180996 times 81689712 step by step
81180996 × 81689712 = 81689712 × (81180996)
+ 81689712 × 6 what gives us 490138272
+ 81689712 × 90 giving us 7352074080
+ 81689712 × 900 that is equal 73520740800
+ 81689712 × 0000 that is equal 0
+ 81689712 × 80000 that is equal 6535176960000
+ 81689712 × 100000 yielding 8168971200000
+ 81689712 × 1000000 that equals 81689712000000
+ 81689712 × 80000000 that equals 6535176960000000

= 6631652183113152
