No problem, we've got 81988441 and 64647756 to multiply
81988441 × 64647756 = 64647756 × (81988441)
+ 64647756 × 1 producing 64647756
+ 64647756 × 40 producing 2585910240
+ 64647756 × 400 which equals 25859102400
+ 64647756 × 8000 giving us 517182048000
+ 64647756 × 80000 giving us 5171820480000
+ 64647756 × 900000 resulting in 58182980400000
+ 64647756 × 1000000 yielding 64647756000000
+ 64647756 × 80000000 that is equal 5171820480000000

= 5300368728588396
