Whats APP Quiz 6

IQ LEVEL TEST

A man wanted 2 enter a CLUB
Every member knew the password,
The man was hidden beside the wall & tried to listen to the password.
A member came, watchman said '12'
Member replied 6,
Watchman opened the door.

Another member came, watchman said '6'
Member replied 3,
Watchman opened the door.

Man thought he got d PASSWORD
He went to the door,
Watchman said '8'
Man replied 4, Watchman didn't open the door.

What was the PASSWORD ???

Answer is in comment box