Alright, let's work through 78316256 times 26840542 step by step
78316256 × 26840542 = 26840542 × (78316256)
+ 26840542 × 6 what gives us 161043252
+ 26840542 × 50 what gives us 1342027100
+ 26840542 × 200 resulting in 5368108400
+ 26840542 × 6000 yielding 161043252000
+ 26840542 × 10000 that is equal 268405420000
+ 26840542 × 300000 giving us 8052162600000
+ 26840542 × 8000000 which equals 214724336000000
+ 26840542 × 70000000 what gives us 1878837940000000

= 2102050758450752
