Alright, let's work through 21847651 times 78001345 step by step
21847651 × 78001345 = 78001345 × (21847651)
+ 78001345 × 1 which equals 78001345
+ 78001345 × 50 resulting in 3900067250
+ 78001345 × 600 that is equal 46800807000
+ 78001345 × 7000 producing 546009415000
+ 78001345 × 40000 which equals 3120053800000
+ 78001345 × 800000 giving us 62401076000000
+ 78001345 × 1000000 that is equal 78001345000000
+ 78001345 × 20000000 which equals 1560026900000000

= 1704146163090595
