Alright, let's work through 4004 times 5145 step by step
4004 × 5145 = 5145 × (4004)
+ 5145 × 4 producing 20580
+ 5145 × 00 giving us 0
+ 5145 × 000 that results in 0
+ 5145 × 4000 giving us 20580000

= 20600580
