Alright, let's work through 8507 times 781 step by step
8507 × 781 = 781 × (8507)
+ 781 × 7 yielding 5467
+ 781 × 00 yielding 0
+ 781 × 500 which equals 390500
+ 781 × 8000 producing 6248000

= 6643967
