A whole number is a non-negative integer, which includes zero and all positive integers. Natural numbers are the set of positive integers starting from 1 (1, 2, 3, ...), so they do not include zero.
From the options given:
- -12 is not a whole number (it's a negative integer).
- 22 is a natural number (and also a whole number).
- 0 is a whole number but not a natural number.
- 3 is a natural number (and also a whole number).
Therefore, the answer is 0, as it is a whole number but not a natural number.