A highly branched polyolefin having olefin derived units; wherein the highly branched polyolefin has: (i) a branching index, g′(vis), of less than about 0.9; (ii) a phase angle, δ, of less than about 55 degrees at a complex modulus of 10 kPa, measured at 190° C.; (iii) a gel content of less than or equal to about 10%; and (iv) a melting point of less than about 135° C.; wherein the highly branched polyolefin is obtained by contacting one or more polyolefins with a free radical generator. The highly branched polyolefin may also comprise a modifying polymer, wherein the modifying polymer may be the similar or dissimilar to the polyolefin. Methods of producing these highly branched polyolefins and blends of these highly branched polyolefins are also disclosed.