New Tai Lue Digit One
HTML Entity Browser Test:

U+19D1 is the Unicode hex value of the character New Tai Lue Digit One, which is categorized as "decimal digit number" in the Unicode 6.0 character table.

Unicode Character Information
Unicode Hex U+19D1
General Category Decimal Digit Number [Code: Nd]
Canonical Combining Class 0
Bidirectional Category L
Numeric Value 1
Mirrored N
Unicode Character Encodings
New Tai Lue Digit One HTML Entity ᧑ (decimal entity), ᧑ (hex entity)
Windows Key Code Alt 6609 or Alt +19D11
Programming Source Code Encodings Python hex: u"\u19D1", Hex for C++ and Java: "\u19D1"
UTF-8 Hexadecimal Encoding 0xE1A791
1 To type a Unicode symbol in Windows, hold down the ALT key and enter the decimal or hexadecimal code provided using the numeric keypad. The decimal alt code (Alt 6609) will only work on computers with support for this Unicode character in the active code page. The hexadecimal alt code (Alt +19D1) will work for all Unicode characters provided Hex input from the numeric keypad is enabled.
* If the New Tai Lue Digit One character does not display correctly in your browser, you may not have a Unicode font on your system that supports this particular symbol.