Alright, let's work through 1591 times 8402 step by step
1591 × 8402 = 8402 × (1591)
+ 8402 × 1 yielding 8402
+ 8402 × 90 that results in 756180
+ 8402 × 500 producing 4201000
+ 8402 × 1000 that equals 8402000

= 13367582
