Whitch number is a perfect cube?

7
25
66***
27

No.

http://www.mathsisfun.com/numbers/cube-root.html

To determine if a number is a perfect cube, we need to check if it can be expressed as the cube of an integer. We'll consider the given numbers one by one:

1. 7 is not a perfect cube because it cannot be expressed as the cube of any integer. To check this, we can try finding the cube root of 7. The cube root of 7 is approximately 1.913, which is not a whole number.

2. 25 is not a perfect cube either. The cube root of 25 is approximately 2.924, again not a whole number.

3. 66 is not a perfect cube. The cube root of 66 is approximately 4.080, still not a whole number.

4. 27 is indeed a perfect cube. The cube root of 27 is 3, which is a whole number.

Therefore, out of the given numbers, only 27 is a perfect cube.