Alright, let's work through 66720864 times 58378634 step by step
66720864 × 58378634 = 58378634 × (66720864)
+ 58378634 × 4 resulting in 233514536
+ 58378634 × 60 resulting in 3502718040
+ 58378634 × 800 which equals 46702907200
+ 58378634 × 0000 which equals 0
+ 58378634 × 20000 that equals 1167572680000
+ 58378634 × 700000 giving us 40865043800000
+ 58378634 × 6000000 producing 350271804000000
+ 58378634 × 60000000 that is equal 3502718040000000

= 3895072899619776
