“I hope you brought your sense of humor,” said Mimi Greeley, greeting a visitor on Wednesday to her apartment, where she was accessorized with a walker, a hot pink feather boa and a tiara on her head.

Not bad for a woman who turned 100 on Thursday.

Mrs. Greeley’s apartment, at the eastern end of 72nd Street in Manhattan, overlooks the East River and Roosevelt Island, the residential sliver in the river that looked much different when she first beheld it in the 1930s as a young nursing student.

“They called it Blackwell’s Island then, and none of those buildings were there,” said Mrs. Greeley, who lives alone. She shops, cooks and cleans for herself, and has ranks of friends and relatives vying to take her to lunch and dinner.

Her mind is sharp, and she is perfectly capable of walking to local restaurants and taking a cab to the doctor’s and the movies.