Home U+2150 to U+218F Number Forms
Glyph for U+218A
Source: Noto Sans Symbols

U+218A Turned Digit Two

U+218A was added to Unicode in version 8.0 (2015). It belongs to the block U+2150 to U+218F Number Forms in the U+0000 to U+FFFF Basic Multilingual Plane.

This character is a Other Symbol and is commonly used, that is, in no specific script.

The glyph is not a composition. It has a Neutral East Asian Width. In bidirectional context it acts as Other Neutral and is not mirrored. In text U+218A behaves as Alphabetic regarding line breaks. It has type Other for sentence and Other for word breaks. The Grapheme Cluster Break is Any.

The Wikipedia has the following information about this codepoint:

The duodecimal system (also known as base 12, dozenal, or, rarely, uncial) is a positional notation numeral system using twelve as its base. The number twelve (that is, the number written as "12" in the base ten numerical system) is instead written as "10" in duodecimal (meaning "1 dozen and 0 units", instead of "1 ten and 0 units"), whereas the digit string "12" means "1 dozen and 2 units" (i.e., the same number that in decimal is written as "14"). Similarly, in duodecimal "100" means "1 gross", "1000" means "1 great gross", and "0.1" means "1 twelfth" (instead of their decimal meanings "1 hundred", "1 thousand", and "1 tenth").

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 number twelve, a superior highly composite number, is the smallest number with four non-trivial 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 3-smooth numbers (a/2b·3c 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 base-10 (which has only 2 and 5 as factors), and also to other proposed bases such as 8 or 16. Base-60 does even better in this respect (the reciprocals of all 5-smooth numbers terminate) but at the cost of unwieldy multiplication tables and a much larger number of symbols to memorize.


System Representation
UTF-8 E2 86 8A
UTF-16 21 8A
UTF-32 00 00 21 8A
URL-Quoted %E2%86%8A
HTML hex reference ↊
Wrong windows-1252 Mojibake ↊


Complete Record

Property Value
Age 8.0 (2015)
Unicode 1 Name
Block Number Forms
General Category Other Symbol
Script Common
Bidirectional Category Other Neutral
Combining Class Not Reordered
Decomposition Type None
Decomposition Mapping Glyph for U+218A Turned Digit Two
Simple Lowercase Mapping Glyph for U+218A Turned Digit Two
Lowercase Mapping Glyph for U+218A Turned Digit Two
Simple Uppercase Mapping Glyph for U+218A Turned Digit Two
Uppercase Mapping Glyph for U+218A Turned Digit Two
Simple Titlecase Mapping Glyph for U+218A Turned Digit Two
Titlecase Mapping Glyph for U+218A Turned Digit Two
Case Folding Glyph for U+218A Turned Digit Two
ASCII Hex Digit
Bidi Control
Bidi Mirrored
Composition Exclusion
Case Ignorable
Changes When Casefolded
Changes When Casemapped
Changes When NFKC Casefolded
Changes When Lowercased
Changes When Titlecased
Changes When Uppercased
Full Composition Exclusion
Default Ignorable Code Point
Emoji Modifier Base
Emoji Component
Emoji Modifier
Emoji Presentation
Extended Pictographic
FC NFKC Closure Glyph for U+218A Turned Digit Two
Grapheme Cluster Break Any
Grapheme Base
Grapheme Extend
Grapheme Link
Hex Digit
ID Continue
ID Start
IDS Binary Operator
IDS Trinary Operator and
Indic Mantra Category
Indic Positional Category NA
Indic Syllabic Category Other
Jamo Short Name
Join Control
Logical Order Exception
Noncharacter Code Point
NFC Quick Check Yes
NFD Quick Check Yes
NFKC Casefold Glyph for U+218A Turned Digit Two
NFKC Quick Check Yes
NFKD Quick Check Yes
Other Alphabetic
Other Default Ignorable Code Point
Other Grapheme Extend
Other ID Continue
Other ID Start
Other Lowercase
Other Math
Other Uppercase
Prepended Concatenation Mark
Pattern Syntax
Pattern White Space
Quotation Mark
Regional Indicator
Sentence Break Other
Soft Dotted
Sentence Terminal
Terminal Punctuation
Unified Ideograph
Variation Selector
Word Break Other
White Space
XID Continue
XID Start
Expands On NFC
Expands On NFD
Expands On NFKC
Expands On NFKD
Bidi Paired Bracket Glyph for U+218A Turned Digit Two
Bidi Paired Bracket Type None
East Asian Width Neutral
Hangul Syllable Type Not Applicable
ISO 10646 Comment
Joining Group No_Joining_Group
Joining Type Non Joining
Line Break Alphabetic
Numeric Type None
Numeric Value not a number
Simple Case Folding Glyph for U+218A Turned Digit Two
Script Extension
Vertical Orientation R