interval
D♭ perfect fifth
D♭lowerA♭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
D♭ up a perfect fifth is A♭: 7 half steps, and 5 letters counting both ends.
Turn it upside down — put the D♭ 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 D♭
D♭ → E♭♭minor second · dissonanceD♭ → E♭major second · dissonanceD♭ → F♭minor third · imperfect consonanceD♭ → Fmajor third · imperfect consonanceD♭ → G♭perfect fourth · perfect consonanceD♭ → Gaugmented fourth · dissonanceD♭ → A♭♭diminished fifth · dissonanceD♭ → B♭♭minor sixth · imperfect consonanceD♭ → B♭major sixth · imperfect consonanceD♭ → C♭minor seventh · dissonanceD♭ → Cmajor seventh · dissonance