interval
E♭ perfect fifth
E♭lowerB♭upperP57 half steps
Seven half steps. Stack twelve of them and you land back where you started, give or take a comma.
On the keyboard
What is true of it
E♭ up a perfect fifth is B♭: 7 half steps, and 5 letters counting both ends.
Turn it upside down — put the E♭ on top — and it becomes a perfect fourth. The two numbers always add to nine, and the two sizes to twelve.
It is a perfect consonance.
Every interval on E♭
E♭ → F♭minor second · dissonanceE♭ → Fmajor second · dissonanceE♭ → G♭minor third · imperfect consonanceE♭ → Gmajor third · imperfect consonanceE♭ → A♭perfect fourth · perfect consonanceE♭ → Aaugmented fourth · dissonanceE♭ → B♭♭diminished fifth · dissonanceE♭ → C♭minor sixth · imperfect consonanceE♭ → Cmajor sixth · imperfect consonanceE♭ → D♭minor seventh · dissonanceE♭ → Dmajor seventh · dissonance