Alright, let's work through 85320819 times 77137653 step by step
85320819 × 77137653 = 77137653 × (85320819)
+ 77137653 × 9 that is equal 694238877
+ 77137653 × 10 yielding 771376530
+ 77137653 × 800 that equals 61710122400
+ 77137653 × 0000 producing 0
+ 77137653 × 20000 resulting in 1542753060000
+ 77137653 × 300000 giving us 23141295900000
+ 77137653 × 5000000 that results in 385688265000000
+ 77137653 × 80000000 which equals 6171012240000000

= 6581447729697807
