Alright, let's work through 1604 times 8523 step by step
1604 × 8523 = 8523 × (1604)
+ 8523 × 4 that is equal 34092
+ 8523 × 00 producing 0
+ 8523 × 600 that is equal 5113800
+ 8523 × 1000 resulting in 8523000

= 13670892
