Alright, let's work through 42168307 times 20451742 step by step
42168307 × 20451742 = 20451742 × (42168307)
+ 20451742 × 7 resulting in 143162194
+ 20451742 × 00 that is equal 0
+ 20451742 × 300 giving us 6135522600
+ 20451742 × 8000 which equals 163613936000
+ 20451742 × 60000 that is equal 1227104520000
+ 20451742 × 100000 that is equal 2045174200000
+ 20451742 × 2000000 that is equal 40903484000000
+ 20451742 × 40000000 which equals 818069680000000

= 862415335340794
