Alright, let's work through 80840340 times 17654013 step by step
80840340 × 17654013 = 17654013 × (80840340)
+ 17654013 × 0 resulting in 0
+ 17654013 × 40 what gives us 706160520
+ 17654013 × 300 that equals 5296203900
+ 17654013 × 0000 what gives us 0
+ 17654013 × 40000 giving us 706160520000
+ 17654013 × 800000 which equals 14123210400000
+ 17654013 × 0000000 giving us 0
+ 17654013 × 80000000 producing 1412321040000000

= 1427156413284420
