A rotor blade of a wind power installation, at least comprising - a first rotor blade component having: - a first end for arranging on the wind power installation, and - a second end for connecting to a second rotor blade component; - a second rotor blade component having: - a first end for arranging on the first rotor blade component, and - a second end wherein - the first rotor blade component can be connected to the second rotor blade component at a separating point to the rotor blade (210, 220), wherein - the rotor blade (210, 220) has an aerodynamically open profile at the separating point, wherein - the rotor blade has a progression with different profiles in the rotor blade longitudinal direction, each profile having a leading edge, a trailing edge, and flow surfaces on the pressure side and the suction side connecting the leading edge and trailing edge, and - the trailing edge in at least one portion in the rotor blade longitudinal direction, in which the separating point lies, - is designed as a thick trailing edge or has flow-influencing components such as Gurney flaps or is designed as a C-shaped or hollow profile in order to provide said aerodynamically open profile, wherein - a direct connection between the leading edge and the trailing edge is referred to as the chord and the length thereof as the profile depth, a greater distance between the profile surface on the pressure side and the suction side perpendicularly to the profile depth is referred to as the profile thickness and a ratio of profile thickness to profile depth is referred to as the relative thickness, wherein a progression of the relative thickness over the rotor blade length is referred to as the thickness progression and the rotor blade is characterized in that a change in the thickness progression in the region of the separating point has a local maximum. - a first rotor blade component having: - a first end for arranging on the wind power installation, and - a second end for connecting to a second rotor blade component; - a first end for arranging on the wind power installation, and - a second end for connecting to a second rotor blade component; - a second rotor blade component having: - a first end for arranging on the first rotor blade component, and - a second end wherein - a first end for arranging on the first rotor blade component, and - a second end wherein - the first rotor blade component can be connected to the second rotor blade component at a separating point to the rotor blade (210, 220), wherein - the rotor blade (210, 220) has an aerodynamically open profile at the separating point, wherein - the rotor blade (210, 220) has an aerodynamically open profile at the separating point, wherein - the rotor blade has a progression with different profiles in the rotor blade longitudinal direction, each profile having a leading edge, a trailing edge, and flow surfaces on the pressure side and the suction side connecting the leading edge and trailing edge, and - the trailing edge in at least one portion in the rotor blade longitudinal direction, in which the separating point lies, - is designed as a thick trailing edge or has flow-influencing components such as Gurney flaps or is designed as a C-shaped or hollow profile in order to provide said aerodynamically open profile, wherein - the trailing edge in at least one portion in the rotor blade longitudinal direction, in which the separating point lies, - is designed as a thick trailing edge or has flow-influencing components such as Gurney flaps or is designed as a C-shaped or hollow profile in order to provide said aerodynamically open profile, wherein - is designed as a thick trailing edge or has flow-influencing components such as Gurney flaps or is designed as a C-shaped or hollow profile in order to provide said aerodynamically open profile, wherein - a direct connection between the leading edge and the trailing edge is referred to as the chord and the length thereof as the profile depth, a greater distance between the profile surface on the pressure side and the suction side perpendicularly to the profile depth is referred to as the profile thickness and a ratio of profile thickness to profile depth is referred to as the relative thickness, wherein a progression of the relative thickness over the rotor blade length is referred to as the thickness progression and the rotor blade is characterized in that a change in the thickness progression in the region of the separating point has a local maximum. a greater distance between the profile surface on the pressure side and the suction side perpendicularly to the profile depth is referred to as the profile thickness and a ratio of profile thickness to profile depth is referred to as the relative thickness, wherein a progression of the relative thickness over the rotor blade length is referred to as the thickness progression and the rotor blade is characterized in that a change in the thickness progression in the region of the separating point has a local maximum.