What 𝟼 means
It is still six, set in a mathematical monospace style.
Its typewriter-like look belongs to a set of digit styles made for mathematics. In a formula, a style can distinguish one mathematical symbol from another, but 𝟼 has no universal extra meaning by itself; the surrounding notation supplies it.
Unicode encoded this family so mathematical style distinctions could survive in plain text. It extends a smaller set of symbols based on letters that older character sets already carried. Using these characters just to imitate a font in ordinary text is an unintended side effect.
Why does 𝟼 turn into 6?
Compatibility normalization reduces it to ordinary 6.
Its compatibility mapping reduces it to the plain digit. NFKC, a Unicode text-cleanup form that removes compatibility distinctions, applies that mapping and drops the monospace style. Keep the distinct character when a formula depends on that style.
In mathematical notation, its monospace style may carry meaning; in ordinary text, it is a specialized visual treatment.
NFKC normalization can turn it into ordinary 6.
Don't confuse it with
4Questions people ask
1Why does 𝟼 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 𝟼
𝟼\1D7FCCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.