Problem 44384. Find the nearest prime number

Happy 5th birthday, Cody! Since 5 is a prime number, let's have some fun looking for other prime numbers.

Given a positive integer x, find the nearest prime number. Keep in mind that the nearest prime may be less than x.

Examples

nearestprime(5) = 5
nearestprime(36) = 37
nearestprime(200) = 199

NOTE: You may ignore cases in which two prime numbers are equally close to x. (e.g., x=12 --> 11 and 13 are both primes).

Solve

Last Solution submitted on Sep 09, 2025

Tran Hiep Dinh on 21 Mar 2019

Test case No. 5
x = 911;
y_correct = 911;

Should the nearest prime number for 911 have been 907?

Show comments

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!