Only the number one.
The HCF is 4
1, 2, 3, 4, 6, 12.
Itself and any of its factors will divide evenly into -72 with no remainders.
1 and 3.
2, 4
3
The number is 24.
Itself and any of its factors
72/36 = 2
1, 3 and 9 will go into both numbers evenly
18 is.
72