Alright, let's work through 81459539 times 81154504 step by step
81459539 × 81154504 = 81154504 × (81459539)
+ 81154504 × 9 yielding 730390536
+ 81154504 × 30 that results in 2434635120
+ 81154504 × 500 producing 40577252000
+ 81154504 × 9000 that is equal 730390536000
+ 81154504 × 50000 that results in 4057725200000
+ 81154504 × 400000 that equals 32461801600000
+ 81154504 × 1000000 resulting in 81154504000000
+ 81154504 × 80000000 yielding 6492360320000000

= 6610808483613656
