Alright, let's work through 3587 times 5120 step by step
3587 × 5120 = 5120 × (3587)
+ 5120 × 7 which equals 35840
+ 5120 × 80 that is equal 409600
+ 5120 × 500 yielding 2560000
+ 5120 × 3000 that equals 15360000

= 18365440
