A cutting insert, comprising: an upper surface; a side surface comprising a front clearance surface and a pair of side clearance surfaces adjacent to the front clearance surface; and an end cutting edge located along an intersection of the upper surface and the front clearance surface, wherein the upper surface comprises an end rake surface that is continuous with the end cutting edge and is inclined downward as departing from the end cutting edge, a pair of front protrusions that is located apart from the end cutting edge and are less apart from each other as departing from the end cutting edge in a top view, a rear protrusion which is further apart from the end cutting edge than the pair of front protrusions in the top view, and which is located in a region between the pair of front protrusions in a side view taken from the front clearance surface, the rear protrusion comprising an ascent portion inclined upward as departing from the end cutting edge, and a pair of intermediate protrusions that is at least partially located between the pair of front protrusions and the rear protrusion in the top view, and wherein top portions of the pair of intermediate protrusions are respectively located between the pair of front protrusions and the rear protrusion, and are higher than top portions of the front protrusions and a top portion of the rear protrusion. an upper surface; a side surface comprising a front clearance surface and a pair of side clearance surfaces adjacent to the front clearance surface; and an end cutting edge located along an intersection of the upper surface and the front clearance surface, wherein the upper surface comprises an end rake surface that is continuous with the end cutting edge and is inclined downward as departing from the end cutting edge, a pair of front protrusions that is located apart from the end cutting edge and are less apart from each other as departing from the end cutting edge in a top view, a rear protrusion which is further apart from the end cutting edge than the pair of front protrusions in the top view, and which is located in a region between the pair of front protrusions in a side view taken from the front clearance surface, the rear protrusion comprising an ascent portion inclined upward as departing from the end cutting edge, and a pair of intermediate protrusions that is at least partially located between the pair of front protrusions and the rear protrusion in the top view, and an end rake surface that is continuous with the end cutting edge and is inclined downward as departing from the end cutting edge, a pair of front protrusions that is located apart from the end cutting edge and are less apart from each other as departing from the end cutting edge in a top view, a rear protrusion which is further apart from the end cutting edge than the pair of front protrusions in the top view, and which is located in a region between the pair of front protrusions in a side view taken from the front clearance surface, the rear protrusion comprising an ascent portion inclined upward as departing from the end cutting edge, and a pair of intermediate protrusions that is at least partially located between the pair of front protrusions and the rear protrusion in the top view, and wherein top portions of the pair of intermediate protrusions are respectively located between the pair of front protrusions and the rear protrusion, and are higher than top portions of the front protrusions and a top portion of the rear protrusion.