"TiK ToK was the first single that I put into this ... up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling ...

The “Delusional” singer took to X on Thursday (Jan. 2) to crow about the fact that her debut single, “Tik Tok,” is back on top again. “It was 15 years ago that I got my first #1 song!