U+2147 "ⅇ" Double-Struck Italic Small E Unicode Character

U+2147 "ⅇ" Double-Struck Italic Small E is a typographic symbol that represents the mathematical constant known as Euler's number, approximately equal to 2.71828, which is the base of the natural logarithm. This character belongs to the Letterlike Symbols block and is designed in a double-struck italic style to distinguish it from a regular lowercase letter "e" used in text. Its primary use is in scientific and mathematical notation, where it provides a clear and unambiguous way to denote this fundamental constant in formulas and equations. The double-struck or "blackboard bold" appearance is a common convention in mathematics to indicate specific sets or constants, ensuring the symbol stands out visually from ordinary variables.

General Properties

Code Point	U+2147
Version Added	3.2
Name	Double-Struck Italic Small E
Block	Letterlike Symbols
General Category	Lowercase Letter
Canonical Combining Class	Not Reordered
Bidirectional Class	Left To Right
Decomposition Type	Font
Decomposition Mapping	"e" U+0065 Latin Small Letter E

Encodings

HTML Decimal Encoding	ⅇ
HTML Hex Encoding	ⅇ
UTF-8 Encoding	0xE2 0x85 0x87
UTF-16 Encoding	0x2147
UTF-32 Encoding	0x00002147
C/C++/Java Escape	\u2147

Unicode Properties

NFC Quick Check	Yes
NFD Quick Check	Yes
Numeric Type	None
Numeric Value	NaN
Line Break	Alphabetic
Lowercase	Yes
Cased	Yes
Changes When NFKC Casefolded	Yes
NFKC Casefold	"e" U+0065 Latin Small Letter E
NFKC Simple Casefold	"e" U+0065 Latin Small Letter E
Script	Common
Script Extensions	Common
Indic Syllabic Category	Other
ID Start	Yes
XID Start	Yes
ID Continue	Yes
XID Continue	Yes
Alphabetic	Yes
Math	Yes
Other Math	Yes
Vertical Orientation	Upright
Grapheme Base	Yes
Grapheme Cluster Break	Other
Word Break	Alphabetic letter
Sentence Break	Lower