Tom I can answer that.
The current 747-400 is capable of low speeds of 125 knots.
Depending on the type of winds around the field it can even go lower and still have incredible maneuverability.
Truly the 747 is one of the most amazing and best designed machines on our current world.
All I can tell you is that they removed the no-gear alarm to be able to go that slow, with full flaps and no gear ;)
It can get very annoying, very fast.
WOOOP WOOOP PULL UP! PULL UP! WOOOP WOOOP
If anyone is interested in knowing a little bit more about the 747s just let me know. I have a set of articles and movies that wxplain very well what it's capable of.