F# 13#11, 2nd inversion (C# in the bass)
Also written as F#13#11/C#.
Notes, from the bass up
C# (bass)EG#B#D#F#A#
The same notes as F# 13#11 (C#, E, G#, B#, D#, F# and A#), rearranged so C# is the lowest note. Use it to move between chords with smaller jumps across the keyboard.