Alright, let's work through 84020145 times 65809499 step by step
84020145 × 65809499 = 65809499 × (84020145)
+ 65809499 × 5 that results in 329047495
+ 65809499 × 40 which equals 2632379960
+ 65809499 × 100 yielding 6580949900
+ 65809499 × 0000 that equals 0
+ 65809499 × 20000 producing 1316189980000
+ 65809499 × 000000 what gives us 0
+ 65809499 × 4000000 which equals 263237996000000
+ 65809499 × 80000000 that results in 5264759920000000

= 5529323648357355
