Alright, let's work through 81948393 times 66732513 step by step
81948393 × 66732513 = 66732513 × (81948393)
+ 66732513 × 3 what gives us 200197539
+ 66732513 × 90 that results in 6005926170
+ 66732513 × 300 that results in 20019753900
+ 66732513 × 8000 giving us 533860104000
+ 66732513 × 40000 that results in 2669300520000
+ 66732513 × 900000 that is equal 60059261700000
+ 66732513 × 1000000 resulting in 66732513000000
+ 66732513 × 80000000 which equals 5338601040000000

= 5468622201201609
