Should be moved to the Simple Questions Thread, but anyways, definitely worth raising. 170-222 should be its Sp.Atk with a Beneficial Nature (AKA Modest) so you're a good 8 points above the minimum.
EV train it and you should end up with at least 400 in Sp.Atk. As for the IVs, unless it has 31 IVs in Sp.Atk, it won't cap at 438. More than likely, it'll cap at 407, if it has 0 Sp.Atk IVs.