No problem, we've got 80413857 and 80580011 to multiply
80413857 × 80580011 = 80580011 × (80413857)
+ 80580011 × 7 which equals 564060077
+ 80580011 × 50 resulting in 4029000550
+ 80580011 × 800 what gives us 64464008800
+ 80580011 × 3000 what gives us 241740033000
+ 80580011 × 10000 what gives us 805800110000
+ 80580011 × 400000 resulting in 32232004400000
+ 80580011 × 0000000 resulting in 0
+ 80580011 × 80000000 that is equal 6446400880000000

= 6479749481612427
