Alright, let's work through 77762975 times 99864025 step by step
77762975 × 99864025 = 99864025 × (77762975)
+ 99864025 × 5 that results in 499320125
+ 99864025 × 70 that equals 6990481750
+ 99864025 × 900 yielding 89877622500
+ 99864025 × 2000 producing 199728050000
+ 99864025 × 60000 that is equal 5991841500000
+ 99864025 × 700000 that equals 69904817500000
+ 99864025 × 7000000 which equals 699048175000000
+ 99864025 × 70000000 giving us 6990481750000000

= 7765723679474375
