Alright, let's work through 81198555 times 98187738 step by step
81198555 × 98187738 = 98187738 × (81198555)
+ 98187738 × 5 which equals 490938690
+ 98187738 × 50 yielding 4909386900
+ 98187738 × 500 that equals 49093869000
+ 98187738 × 8000 resulting in 785501904000
+ 98187738 × 90000 yielding 8836896420000
+ 98187738 × 100000 producing 9818773800000
+ 98187738 × 1000000 that equals 98187738000000
+ 98187738 × 80000000 what gives us 7855019040000000

= 7972702444318590
