Alright, let's work through 79781915 times 80506662 step by step
79781915 × 80506662 = 80506662 × (79781915)
+ 80506662 × 5 yielding 402533310
+ 80506662 × 10 producing 805066620
+ 80506662 × 900 that equals 72455995800
+ 80506662 × 1000 producing 80506662000
+ 80506662 × 80000 giving us 6440532960000
+ 80506662 × 700000 that equals 56354663400000
+ 80506662 × 9000000 that results in 724559958000000
+ 80506662 × 70000000 that is equal 5635466340000000

= 6422975664617730
