Alright, let's work through 80963469 times 79100073 step by step
80963469 × 79100073 = 79100073 × (80963469)
+ 79100073 × 9 resulting in 711900657
+ 79100073 × 60 giving us 4746004380
+ 79100073 × 400 that results in 31640029200
+ 79100073 × 3000 what gives us 237300219000
+ 79100073 × 60000 giving us 4746004380000
+ 79100073 × 900000 which equals 71190065700000
+ 79100073 × 0000000 resulting in 0
+ 79100073 × 80000000 yielding 6328005840000000

= 6404216308233237
