No problem, we've got 81810945 and 78315796 to multiply
81810945 × 78315796 = 78315796 × (81810945)
+ 78315796 × 5 that is equal 391578980
+ 78315796 × 40 which equals 3132631840
+ 78315796 × 900 producing 70484216400
+ 78315796 × 0000 that results in 0
+ 78315796 × 10000 that is equal 783157960000
+ 78315796 × 800000 producing 62652636800000
+ 78315796 × 1000000 that is equal 78315796000000
+ 78315796 × 80000000 yielding 6265263680000000

= 6407089279187220
