Alright, let's work through 13480381 times 90520260 step by step
13480381 × 90520260 = 90520260 × (13480381)
+ 90520260 × 1 that is equal 90520260
+ 90520260 × 80 giving us 7241620800
+ 90520260 × 300 resulting in 27156078000
+ 90520260 × 0000 producing 0
+ 90520260 × 80000 that is equal 7241620800000
+ 90520260 × 400000 that equals 36208104000000
+ 90520260 × 3000000 that equals 271560780000000
+ 90520260 × 10000000 yielding 905202600000000

= 1220247593019060
