Bb 13#11, 5th inversion (E in the bass)
Also written as Bb13#11/E.
Notes, from the bass up
E (bass)GA#DE#G#B#
The same notes as Bb 13#11 (E, G, A#, D, E#, G# and B#), rearranged so E is the lowest note. Use it to move between chords with smaller jumps across the keyboard.