U+0006, 
<control-0006>
(Abbreviation: ACK)
[unassigned: U+0000–U+0005][unassigned: U+0007–U+001F]
Basic Latin
[U+0020]
Presentations of 6︎
Text
style
Emoji
style
6︎ 6️
Note: Character's appearance
may be different on each system.
Text style is forced with &#xFE0E;
and emoji style with &#xFE0F;

Emoji