1 it's both a perfect square and a perfect cube!

$972 = 6^{2} \times 3^{3}, 900 = 30^{2} \times 1^{3}, 968 = 11^{2} \times 2^{3}, 961 = 31^{2} \times 1^{3}$ .

On the other hand, $980 = 7^{2} \times 2^{2} \times 5$ cannot be written as the product of a perfect square and a perfect cube, as none of its divisors other than $1$ is a perfect cube and $980$ itself is not a perfect square.