Tibetan Digit One
HTML Entity Browser Test:

U+0F21 is the Unicode hex value of the character Tibetan Digit One, which is categorized as "decimal digit number" in the Unicode 6.0 character table.

Unicode Character Information
Unicode Hex U+0F21
General Category Decimal Digit Number [Code: Nd]
Canonical Combining Class 0
Bidirectional Category L
Numeric Value 1
Mirrored N
Unicode Character Encodings
Tibetan Digit One HTML Entity ༡ (decimal entity), ༡ (hex entity)
Windows Key Code Alt 3873 or Alt +0F211
Programming Source Code Encodings Python hex: u"\u0F21", Hex for C++ and Java: "\u0F21"
UTF-8 Hexadecimal Encoding 0xE0BCA1
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 3873) will only work on computers with support for this Unicode character in the active code page. The hexadecimal alt code (Alt +0F21) will work for all Unicode characters provided Hex input from the numeric keypad is enabled.
* If the Tibetan 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.