What is the prefix of not handled properly?

There isn't a single, universally accepted prefix for "not handled properly."

Here's why:

* "Not handled properly" is a phrase with a specific meaning. It's not a standalone word that can be broken down with prefixes.

* Prefixes are usually attached to words to modify their meaning. We can't really attach a prefix to "handled" without changing its meaning significantly.

Instead of a prefix, you might consider using a word or phrase that conveys the same meaning, like:

* Mismanaged

* Improperly handled

* Negligently handled

* Unattended

* Unresolved

* Inadequate

The best choice will depend on the specific context of your writing.