Crack the code . Can you. Then you will be genius.
The number is
From the fourth clue, one of $3817$ is correct and well placed. It can't be $1$ (that would contradict the third clue) or $3$ or $7$ (that would contradict the second clue), so it must be $8$ in the second place.
From the second clue, two numbers are correct and well placed. We know $3$ and $7$ are not in the solution, so it must be $6$ in the first place and $4$ in the last place.
Now the third clue is valid with $6$ correct but wrongly placed.
Finally, in the first clue, $4$ is wrongly placed, and $3$ and $9$ are not part of the solution, so the last number must be $2$ in the third place.