What name does the Epic of Gilgamesh give its survivor of the great flood?

The Epic of Gilgamesh calls its survivor of the great flood Utnapishtim. In the flood story within the epic, the god Ea warns Utnapishtim to build a large boat, preserve life, and survive the coming catastrophe.

Utnapishtim’s story is one of the best-known Mesopotamian flood traditions related to the Noah narrative. After the flood, he and his wife receive immortality. When Gilgamesh seeks the secret of avoiding death, Utnapishtim tells him the flood story and tests him with a challenge involving sleep.

The name is associated with the Akkadian version of the tradition. A closely related earlier Babylonian account in the Epic of Atrahasis features a survivor named Atrahasis, while the Sumerian flood story names Ziusudra. These are distinct literary traditions and names, so they should not be treated as interchangeable answers.