Alright, let's work through 83145585 times 66899240 step by step
83145585 × 66899240 = 66899240 × (83145585)
+ 66899240 × 5 producing 334496200
+ 66899240 × 80 giving us 5351939200
+ 66899240 × 500 yielding 33449620000
+ 66899240 × 5000 that results in 334496200000
+ 66899240 × 40000 resulting in 2675969600000
+ 66899240 × 100000 which equals 6689924000000
+ 66899240 × 3000000 which equals 200697720000000
+ 66899240 × 80000000 yielding 5351939200000000

= 5562376445855400
