With an apparent magnitude of about 4.5, the star is faintly visible to the naked eye (see Bortle scale).

Parallax estimates made by the Hipparcos spacecraft put it at a fairly close distance of about 92.1 light-years (28.2 parsecs) away from the Earth.

[12] It is also a Delta Scuti variable, and its apparent magnitude varies from 4.47 to 4.52.

[3] 21 Leonis Minoris has an infrared excess, suggesting a debris disk around it.

[10] The black body fit has a temperature of 60 K with an orbital radius of 62 AU.