piano chord
A♯m
A♯1C♯♭3E♯5
The major triad with its third lowered by a half step.
Written the other way round it is B♭m — the same twelve keys on a piano, a different piece of notation.
What is true of it
A♯m is A♯, C♯ and E♯ — 1, b3 and 5 counted from A♯.
On an instrument that cannot reach all 3, the 5 goes first, in that order.