Mishras factory and Forgotten Ancient

[Cownose]

If I activate a Mishra's Factory during my upkeep and move +1/+1 counters on it from Forgotten Ancient, will the counters stay when the Factory reverts to being a land? If I moved 5 counters and reactivated the Factory on a later turn will it be a 7/7 or do the counters drop off because it is no longer a legal card type?

[Toad]

The counters stay.