Alright, let's work through 20307457 times 28758055 step by step
20307457 × 28758055 = 28758055 × (20307457)
+ 28758055 × 7 yielding 201306385
+ 28758055 × 50 resulting in 1437902750
+ 28758055 × 400 producing 11503222000
+ 28758055 × 7000 that is equal 201306385000
+ 28758055 × 00000 that is equal 0
+ 28758055 × 300000 yielding 8627416500000
+ 28758055 × 0000000 that results in 0
+ 28758055 × 20000000 that is equal 575161100000000

= 584002965316135
