Alright, let's work through 1593 times 7647 step by step
1593 × 7647 = 7647 × (1593)
+ 7647 × 3 giving us 22941
+ 7647 × 90 that is equal 688230
+ 7647 × 500 what gives us 3823500
+ 7647 × 1000 that equals 7647000

= 12181671
