Alright, let's work through 1613 times 2631 step by step
1613 × 2631 = 2631 × (1613)
+ 2631 × 3 resulting in 7893
+ 2631 × 10 what gives us 26310
+ 2631 × 600 yielding 1578600
+ 2631 × 1000 giving us 2631000

= 4243803
