The CJK Unified Ideographs Extension A block spans U+3400–U+4DBF, 6,592 codepoints in Plane 0 (Basic Multilingual Plane). Every one of them is assigned in Unicode 16.0.
All of its characters belong to the Han script.
By general category: 6,592 other letters (Lo).
The first 6,582 arrived in Unicode 3.0 (1999); later additions came in 13.0 (10).
6,592 characters are East Asian Wide or Fullwidth and take two columns in terminals.