A centicube is a cube measuring 1cm x 1cm x 1cm or 1cm3
1 centicube is 1 cm3.
100
A centicube is not a recognised measure of volume.
"centicube" is not really a proper English word but if we take that you mean a cube measuring 1cm x 1cm x 1cm or 1cm3, then that volume has no inherent mass or weight. However, if it is a volume of some material then it will weigh varying amounts, depending on the density of the material. Each material will weigh differently.
You can't convert that very accurately. ha is 10, 000m squared. 1 ml equals one centicube. 100m x 100m equals one ha. 10 000 x 10 000 equals one ha. So, there are 100 000 000 ml in a ha. This is incorrect. You cannot ml to ha. 1 mL equals one centicube, not one centimetre. So, you cannot convert ha to ml.