Alright, let's work through 2646 times 5907 step by step
2646 × 5907 = 5907 × (2646)
+ 5907 × 6 which equals 35442
+ 5907 × 40 resulting in 236280
+ 5907 × 600 that results in 3544200
+ 5907 × 2000 yielding 11814000

= 15629922
