CotEditor can inspect the information about the selected character. Select exactly a single character and choose Inspect Character in the Text menu or press the Command-Option-I keys.
In the inspector, the character in close-up, the Unicode character name, block name, general category, and the Unicode code point will be displayed. It shows also UTF-16 codes of each character in braces if the character is a surrogate pair. If the selected letter consists actually of multiple Unicode characters, only the code points and Unicode name will be listed-up.