Ab Major 9#11, 4th inversion (A# in the bass)
Also written as Abmaj9#11/A#.
Notes, from the bass up
A# (bass)DG#B#D#G
The same notes as Ab Major 9#11 (A#, D, G#, B#, D# and G), rearranged so A# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.