This character is a Decimal Number and is mainly used in the Javanese script. The codepoint has the decimal value 9.
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. This number joins with other adjacent letters and numbers to form a word. U+A9D9 forms an orthographic syllable in Brahmic scripts with similar characters, which prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
9 (nine) is the natural number following 8 and preceding 10.
Representations
System
Representation (click value to copy)
Nº
43481
UTF-8
EA A7 99
UTF-16
A9 D9
UTF-32
00 00 A9 D9
URL-Quoted
%EA%A7%99
HTML hex reference
꧙
Wrong windows-1252 Mojibake
꧙
Encoding: GB18030 (hex bytes)
82 37 98 34
RFC 5137
\u'A9D9'
Bash and Zsh inside echo -e
\uA9D9
C and C++
\uA9D9
C#
\uA9D9
CSS
\00A9D9
Excel
=UNICHAR(43481)
Go
\uA9D9
JavaScript
\uA9D9
Modern JavaScript since ES6
\u{a9d9}
JSON
\uA9D9
Java
\uA9D9
Lua
\u{A9D9}
Matlab
char(43481)
Perl
"\x{A9D9}"
PHP
\u{a9d9}
PostgreSQL
U&'\A9D9'
PowerShell
`u{A9D9}
Python
\uA9D9
Ruby
\u{a9d9}
Rust
\u{a9d9}
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