Maybe is you ask the question like this:

If a person with a micropenis is in a room, how many men are needed in that room to have a 50% chance of someone else in there also with a micropenis? And how many women in that room are needed for a 50% chance a woman has a bigger clitoris than that person's micropenis?

Or:

How many men in a room are needed to have a 50% chance someone else has the same penis size?