Yes, twenty one are both separate words.
Network TwentyOne was created in 1989.
Twentyone and five tenths or twentyone and a half
0.42
icosikaihenagon
Twentyone follows twenty
no
3over7
a third of 21 is 7
Channel two-twentyone
A polygon with 21 sides is called an Icosagon.
14 of them.
No, if they are separate words they are not compound.