C 13#11, 6th inversion (A in the bass)
Also written as C13#11/A.
Notes, from the bass up
A (bass)CEGBbDF#
The same notes as C 13#11 (A, C, E, G, Bb, D and F#), rearranged so A is the lowest note. Use it to move between chords with smaller jumps across the keyboard.