Bb 13#11, 6th inversion (G in the bass)
Also written as Bb13#11/G.
Notes, from the bass up
G (bass)A#DE#G#B#E
The same notes as Bb 13#11 (G, A#, D, E#, G#, B# and E), rearranged so G is the lowest note. Use it to move between chords with smaller jumps across the keyboard.