Alright, let's work through 90738819 times 21510659 step by step
90738819 × 21510659 = 21510659 × (90738819)
+ 21510659 × 9 resulting in 193595931
+ 21510659 × 10 giving us 215106590
+ 21510659 × 800 giving us 17208527200
+ 21510659 × 8000 that is equal 172085272000
+ 21510659 × 30000 that results in 645319770000
+ 21510659 × 700000 that equals 15057461300000
+ 21510659 × 0000000 yielding 0
+ 21510659 × 90000000 that is equal 1935959310000000

= 1951851793571721
