Stochastic local operations and classical communication invariant and the residual entanglement for n qubits

We find an invariant for n qubits and propose residual entanglement for n qubits by means of the invariant. Thus, we establish a relation between stochastic local operations and classical communication (SLOCC) entanglement and residual entanglement. Invariant and residual entanglement can be used for SLOCC entanglement classification of n qubits.