the state of being unchanging or permanent

अपरिवर्तनीयता

English Usage: Her changelessness gave her a sense of stability in an ever-changing world.

Hindi Usage: उसकी अपरिवर्तनीयता ने उसे एक परिवर्तनशील दुनिया में स्थिरता का अहसास कराया।