No problem, we've got 8515 and 8400 to multiply
8515 × 8400 = 8400 × (8515)
+ 8400 × 5 giving us 42000
+ 8400 × 10 giving us 84000
+ 8400 × 500 giving us 4200000
+ 8400 × 8000 that is equal 67200000

= 71526000
