Alright, let's work through 3644 times 4257 step by step
3644 × 4257 = 4257 × (3644)
+ 4257 × 4 yielding 17028
+ 4257 × 40 that equals 170280
+ 4257 × 600 that is equal 2554200
+ 4257 × 3000 that equals 12771000

= 15512508
