Alright, let's work through 72721459 times 73637257 step by step
72721459 × 73637257 = 73637257 × (72721459)
+ 73637257 × 9 resulting in 662735313
+ 73637257 × 50 yielding 3681862850
+ 73637257 × 400 resulting in 29454902800
+ 73637257 × 1000 what gives us 73637257000
+ 73637257 × 20000 giving us 1472745140000
+ 73637257 × 700000 that is equal 51546079900000
+ 73637257 × 2000000 resulting in 147274514000000
+ 73637257 × 70000000 which equals 5154607990000000

= 5355008765797963
