What is "achyuta"

In Hinduism, Achyuta ( IAST: ) is another name of Vishnu and appears as the 100th and 318th names in the Vishnu sahasranama. It is also often used in the Bhagavad Gita as a personal name of Krishna. According to Adi Shankara's commentary on the 1000 Names of Vishnu, Achyuta means "one who will never lose his inherent nature and powers". The name also means "immovable", "unchangeable", and as such is used for "the One who is without the six transformations, beginning with birth".