Factorial factor refers to multiplying 1 by 2 times 3 times 4 to get the desired number.

For example, if the required number is 4, the factorial formula is 1×2×3×4, and the product is 24, that is, the factorial of 4. For example, if the required number is 6, the factorial formula is 1× 2× 3× …× 6, and the product is 720, that is, the factorial of 6. For example,