Gucci Mane -- ARRESTED ... Guns, Drugs & Threatening Cops

Gucci Mane was arrested this morning for allegedly cussing out a couple of cops in Atlanta while in possession of weed and a gun ... TMZ has learned.

Gucci Mane -- real name Radric Davis -- was taken into custody at 12:05 am this morning after one of his friends complained to cops about his erratic behavior.

According to the report -- the friend waved down police to help out ... but when they approached Gucci he began "cursing and threatening them."

We're told he was immediately taken into custody and police found a small amount of marijuana on the 33-year old rapper ... as well as a handgun.

GM was booked for carrying a concealed weapon, disorderly conduct and marijuana possession ... then taken to a nearby hospital as a precaution.