Alright, let's work through 21307329 times 24000831 step by step
21307329 × 24000831 = 24000831 × (21307329)
+ 24000831 × 9 that results in 216007479
+ 24000831 × 20 which equals 480016620
+ 24000831 × 300 resulting in 7200249300
+ 24000831 × 7000 resulting in 168005817000
+ 24000831 × 00000 which equals 0
+ 24000831 × 300000 giving us 7200249300000
+ 24000831 × 1000000 that is equal 24000831000000
+ 24000831 × 20000000 which equals 480016620000000

= 511393602390399
