No problem, we've got 80904475 and 15621603 to multiply
80904475 × 15621603 = 15621603 × (80904475)
+ 15621603 × 5 which equals 78108015
+ 15621603 × 70 which equals 1093512210
+ 15621603 × 400 that equals 6248641200
+ 15621603 × 4000 yielding 62486412000
+ 15621603 × 00000 that is equal 0
+ 15621603 × 900000 that is equal 14059442700000
+ 15621603 × 0000000 producing 0
+ 15621603 × 80000000 yielding 1249728240000000

= 1263857589373425
