Extremely hard quizz: Find out the missing number

Intellectual challenge: Find the missing number in the circle!
Let’s challenge yourself with this interesting logic problem. Looking at the circle with the numbers arranged, can you find the missing number in the blank box?

Suggest:

Look closely at the numbers around the empty box.
Look for relationships between groups of numbers in the circle.
Use logic and reasoning skills to come up with the correct answer.
How long can you solve this problem? Please share your results and solutions in the comments section below. Good luck!

9 is the answer

Bonus:
This problem can have many different solutions. Try to find as many solutions as possible to practice your logical thinking.
You can share this problem with your friends and solve the puzzle together.
Note:
This problem is for entertainment and thinking purposes only.