The actress and singer says she's "never really cared" about numbers but that "it can be a little heavy".
Selena made the comments, reported in The Hollywood Reporter, at Universal Music Group and Thrive Global's Music and Health Conference.
Last year, she released a documentary about her health and mental wellbeing after being diagnosed with lupus.
Selena has 429 million followers on Instagram - more than her bestie Taylor Swift who has 272 million and Kylie Jenner, the previous title holder, who is followed by 399 million people.
The 31-year-old says fans have reached out to her about their own struggles to tell her how her music has helped them through difficult times.