WHAT 1 POP HIT STAYED NUMBER ONE THE LONGEST?

The pop hit that stayed at number one the longest on the Billboard Hot 100 is "Old Town Road" by Lil Nas X, featuring Billy Ray Cyrus. It held the top position for 19 consecutive weeks in 2019. The song's unique blend of country and hip-hop, along with its viral popularity on social media, contributed to its record-breaking run.