Alright, let's work through 80369978 times 15718170 step by step
80369978 × 15718170 = 15718170 × (80369978)
+ 15718170 × 8 that results in 125745360
+ 15718170 × 70 resulting in 1100271900
+ 15718170 × 900 that is equal 14146353000
+ 15718170 × 9000 that equals 141463530000
+ 15718170 × 60000 which equals 943090200000
+ 15718170 × 300000 which equals 4715451000000
+ 15718170 × 0000000 that results in 0
+ 15718170 × 80000000 that equals 1257453600000000

= 1263268977100260
