Code point
U+2121
Glyph appearance depends on your fonts.
U+2121
So<compat> 0054 0045 004CU+2121 TELEPHONE SIGN is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the Letterlike Symbols block.
Choose the representation you need, then copy its value.
U+2121
8481
℡
℡
E2 84 A1
2121
00002121
%E2%84%A1
\u2121
\u2121
\u2121
\2121