Hard to tell from the pic without seeing the under side but it looks like a haddoni and not a gigantea. Haddonis are not as hard to keep as gigantea. They are fish eaters though and may not play well with those other anemones. Mixing anemones can sometimes cause problems but I mostly see the it magnificas and giganteas. You may want to run poly filter and carbon in case, that sometimes can help...
That is a very beautiful anemone and looks to be healthy.