Alright, let's work through 81976931 times 53787129 step by step
81976931 × 53787129 = 53787129 × (81976931)
+ 53787129 × 1 what gives us 53787129
+ 53787129 × 30 that is equal 1613613870
+ 53787129 × 900 producing 48408416100
+ 53787129 × 6000 which equals 322722774000
+ 53787129 × 70000 giving us 3765099030000
+ 53787129 × 900000 which equals 48408416100000
+ 53787129 × 1000000 producing 53787129000000
+ 53787129 × 80000000 that equals 4302970320000000

= 4409303762721099
