Alright, let's work through 21022505 times 79859077 step by step
21022505 × 79859077 = 79859077 × (21022505)
+ 79859077 × 5 resulting in 399295385
+ 79859077 × 00 that is equal 0
+ 79859077 × 500 that results in 39929538500
+ 79859077 × 2000 which equals 159718154000
+ 79859077 × 20000 yielding 1597181540000
+ 79859077 × 000000 that results in 0
+ 79859077 × 1000000 which equals 79859077000000
+ 79859077 × 20000000 yielding 1597181540000000

= 1678837845527885
