Alright, let's work through 81213751 times 79540738 step by step
81213751 × 79540738 = 79540738 × (81213751)
+ 79540738 × 1 yielding 79540738
+ 79540738 × 50 what gives us 3977036900
+ 79540738 × 700 producing 55678516600
+ 79540738 × 3000 yielding 238622214000
+ 79540738 × 10000 resulting in 795407380000
+ 79540738 × 200000 that results in 15908147600000
+ 79540738 × 1000000 that is equal 79540738000000
+ 79540738 × 80000000 yielding 6363259040000000

= 6459801690288238
