Alright, let's work through 1621 times 2187 step by step
1621 × 2187 = 2187 × (1621)
+ 2187 × 1 which equals 2187
+ 2187 × 20 giving us 43740
+ 2187 × 600 giving us 1312200
+ 2187 × 1000 producing 2187000

= 3545127
