Alright, let's work through 79987567 times 81219376 step by step
79987567 × 81219376 = 81219376 × (79987567)
+ 81219376 × 7 what gives us 568535632
+ 81219376 × 60 that equals 4873162560
+ 81219376 × 500 what gives us 40609688000
+ 81219376 × 7000 what gives us 568535632000
+ 81219376 × 80000 yielding 6497550080000
+ 81219376 × 900000 which equals 73097438400000
+ 81219376 × 9000000 that equals 730974384000000
+ 81219376 × 70000000 giving us 5685356320000000

= 6496540279498192
