Instagram does not let public accounts hide their followers list. But you have options.
Make your account private
Only approved followers can see your followers and following lists. See make your Instagram private.
Remove specific followers
Followers → Remove.
Block people
Blocked accounts cannot see your profile at all.
Hide like counts
You can hide like counts on posts, though not follower counts.
For businesses and creators
Accounts must be public. Focus on a healthy follower base instead of hiding it.
Grow your Instagram with real people
ViralSocialUp finds people who are genuinely interested in your niche. No bots, no password needed. Check your free growth preview first.