Alright, let's work through 80816909 times 47510409 step by step
80816909 × 47510409 = 47510409 × (80816909)
+ 47510409 × 9 giving us 427593681
+ 47510409 × 00 resulting in 0
+ 47510409 × 900 that is equal 42759368100
+ 47510409 × 6000 yielding 285062454000
+ 47510409 × 10000 producing 475104090000
+ 47510409 × 800000 which equals 38008327200000
+ 47510409 × 0000000 resulting in 0
+ 47510409 × 80000000 which equals 3800832720000000

= 3839644400705781
