Alright, let's work through 40021309 times 91087498 step by step
40021309 × 91087498 = 91087498 × (40021309)
+ 91087498 × 9 that results in 819787482
+ 91087498 × 00 that equals 0
+ 91087498 × 300 resulting in 27326249400
+ 91087498 × 1000 giving us 91087498000
+ 91087498 × 20000 that results in 1821749960000
+ 91087498 × 000000 yielding 0
+ 91087498 × 0000000 giving us 0
+ 91087498 × 40000000 which equals 3643499920000000

= 3645440903494882
