Alright, let's work through 2907 times 1581 step by step
2907 × 1581 = 1581 × (2907)
+ 1581 × 7 producing 11067
+ 1581 × 00 which equals 0
+ 1581 × 900 yielding 1422900
+ 1581 × 2000 that is equal 3162000

= 4595967
