Alright, let's work through 85398178 times 83641609 step by step
85398178 × 83641609 = 83641609 × (85398178)
+ 83641609 × 8 resulting in 669132872
+ 83641609 × 70 resulting in 5854912630
+ 83641609 × 100 that equals 8364160900
+ 83641609 × 8000 which equals 669132872000
+ 83641609 × 90000 what gives us 7527744810000
+ 83641609 × 300000 resulting in 25092482700000
+ 83641609 × 5000000 producing 418208045000000
+ 83641609 × 80000000 that results in 6691328720000000

= 7142841013588402
