Alright, let's work through 3613 times 9991 step by step
3613 × 9991 = 9991 × (3613)
+ 9991 × 3 producing 29973
+ 9991 × 10 that is equal 99910
+ 9991 × 600 producing 5994600
+ 9991 × 3000 giving us 29973000

= 36097483
