Alright, let's work through 39981197 times 64803671 step by step
39981197 × 64803671 = 64803671 × (39981197)
+ 64803671 × 7 what gives us 453625697
+ 64803671 × 90 resulting in 5832330390
+ 64803671 × 100 what gives us 6480367100
+ 64803671 × 1000 giving us 64803671000
+ 64803671 × 80000 resulting in 5184293680000
+ 64803671 × 900000 what gives us 58323303900000
+ 64803671 × 9000000 which equals 583233039000000
+ 64803671 × 30000000 giving us 1944110130000000

= 2590928336574187
