Alright, let's work through 79889980 times 64027698 step by step
79889980 × 64027698 = 64027698 × (79889980)
+ 64027698 × 0 resulting in 0
+ 64027698 × 80 giving us 5122215840
+ 64027698 × 900 that is equal 57624928200
+ 64027698 × 9000 that is equal 576249282000
+ 64027698 × 80000 that is equal 5122215840000
+ 64027698 × 800000 resulting in 51222158400000
+ 64027698 × 9000000 resulting in 576249282000000
+ 64027698 × 70000000 resulting in 4481938860000000

= 5115171512666040
