How many close friends are needed atleast?

one close friend in the physical area one spend most of the time is required.He could talk,especially in person with that person during that period.Such key physical areas are mainly of two: your abode and work/business or study place. It is not necessary that you should have a lifelong friend. It's ok to make new close friends as life moves along, situation changes, you move to somewhere else, move to a new job. However, try to make the friend as quickly as you could say within a month.

Since one( 1)is mandatory requirement for human being, it is better to have 3such friends in your key physical area so that no one feels much pressure.In this category, parents and family members,relatives come too.
You need another 1 friend to go out or celebrate festive occasion in person.Again here 3 is good for backups. Such friend is supposed to live within easy 30 minutes communication zone.In this category, parents and family members,relatives come too.

You need 1 friend to talk life events. This friend may live near or far butyou would be easily and cheaply avail of that friend by any mode(in person,tel,text,email,chat whatever). For safety here as well 3 such friends is good. In this category,parents and family members,relatives come too.

Therefore, it could be summarized that one need minimum 3 close friends.However the required 3 friends may be fulfilled by one person.Here comes the life partner, it is a requirement and that's why marriage or living together or girl friend-boy friend concept comes up. For safety reason, each category it is better to have 3 persons. Therefore 9 close friends means you are sufficiently covered for your emotional needs.