U+218A Turned Digit Two
U+218A was added in Unicode version 8.0 in 2015. It belongs to the block
This character is a Other Symbol and is commonly used, that is, in no specific script.
The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. The word that U+218A forms with similar adjacent characters prevents a line break inside it.
The Wikipedia has the following information about this codepoint:
The duodecimal system, also known as base twelve or dozenal, is a positional numeral system using twelve as its base. In duodecimal, the number twelve is denoted "10", meaning 1 twelve and 0 units; in the decimal system, this number is instead written as "12" meaning 1 ten and 2 units, and the string "10" means ten. In duodecimal, "100" means twelve squared, "1000" means twelve cubed, and "0.1" means a twelfth.
Various symbols have been used to stand for ten and eleven in duodecimal notation; this page uses A and B, as in hexadecimal, which make a duodecimal count from zero to twelve read 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, 10. The Dozenal Societies of America and Great Britain (organisations promoting the use of duodecimal) use turned digits in their published material: 2 (a turned 2) for ten and 3 (a turned 3) for eleven.
The number twelve, a superior highly composite number, is the smallest number with four nontrivial factors (2, 3, 4, 6), and the smallest to include as factors all four numbers (1 to 4) within the subitizing range, and the smallest abundant number. All multiples of reciprocals of 3smooth numbers (a/2^{b}·3^{c} where a,b,c are integers) have a terminating representation in duodecimal. In particular, +1/4 (0.3), +1/3 (0.4), +1/2 (0.6), +2/3 (0.8), and +3/4 (0.9) all have a short terminating representation in duodecimal. There is also higher regularity observable in the duodecimal multiplication table. As a result, duodecimal has been described as the optimal number system.
In these respects, duodecimal is considered superior to decimal, which has only 2 and 5 as factors, and other proposed bases like octal or hexadecimal. Sexagesimal (base sixty) does even better in this respect (the reciprocals of all 5smooth numbers terminate), but at the cost of unwieldy multiplication tables and a much larger number of symbols to memorize.
Representations
System  Representation 

Nº  8586 
UTF8  E2 86 8A 
UTF16  21 8A 
UTF32  00 00 21 8A 
URLQuoted  %E2%86%8A 
HTML hex reference  ↊ 
Wrong windows1252 Mojibake  â†Š 
Encoding: GB18030 (hex bytes)  81 36 C6 36 
Elsewhere
Complete Record
Property  Value 

8.0 (2015)  
TURNED DIGIT TWO  
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