Ab 13b9, 5th inversion (E# in the bass)
Also written as Ab13b9/E#.
Notes, from the bass up
E# (bass)G#B#D#F#A
The same notes as Ab 13b9 (E#, G#, B#, D#, F# and A), rearranged so E# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.