No problem, we've got 81199412 and 10327990 to multiply
81199412 × 10327990 = 10327990 × (81199412)
+ 10327990 × 2 what gives us 20655980
+ 10327990 × 10 giving us 103279900
+ 10327990 × 400 which equals 4131196000
+ 10327990 × 9000 that equals 92951910000
+ 10327990 × 90000 what gives us 929519100000
+ 10327990 × 100000 resulting in 1032799000000
+ 10327990 × 1000000 that results in 10327990000000
+ 10327990 × 80000000 that is equal 826239200000000

= 838626715141880
