This character is a Other Letter and is mainly used in the Limbu script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+1904 forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
The Limbu script (also Sirijanga script) is used to write the Limbu language. It is a Brahmic type abugida.
Representations
System
Representation (click value to copy)
Nº
6404
UTF-8
E1 A4 84
UTF-16
19 04
UTF-32
00 00 19 04
URL-Quoted
%E1%A4%84
HTML hex reference
ᤄ
Wrong windows-1252 Mojibake
ᤄ
Encoding: GB18030 (hex bytes)
81 34 EC 38
RFC 5137
\u'1904'
Bash and Zsh inside echo -e
\u1904
C and C++
\u1904
C#
\u1904
CSS
\001904
Excel
=UNICHAR(6404)
Go
\u1904
JavaScript
\u1904
Modern JavaScript since ES6
\u{1904}
JSON
\u1904
Java
\u1904
Lua
\u{1904}
Matlab
char(6404)
Perl
"\x{1904}"
PHP
\u{1904}
PostgreSQL
U&'\1904'
PowerShell
`u{1904}
Python
\u1904
Ruby
\u{1904}
Rust
\u{1904}
Click the star button next to each label to set this representation as favorite or remove it from the favorites. Favorites will be shown initially. (Favorites are stored locally on your computer and never sent over the internet.)