Alright, let's work through 640594 times 40536262 step by step
640594 × 40536262 = 40536262 × (640594)
+ 40536262 × 4 which equals 162145048
+ 40536262 × 90 producing 3648263580
+ 40536262 × 500 yielding 20268131000
+ 40536262 × 0000 what gives us 0
+ 40536262 × 40000 giving us 1621450480000
+ 40536262 × 600000 giving us 24321757200000

= 25967286219628
