Foundations Working with digits and divisors
34. Check Whether a Number Is Prime
Medium
Given a positive integer n, return true if n is prime, and false otherwise.
A number is prime when it is greater than 1 and its only divisors are 1 and itself. So 2, 3, 5 and 7 are prime. 6 is not, because 2 and 3 divide it. 1 is not prime either.
Example 1
Input: n = 91
Output:
falseExplanation: 91 = 7 × 13, so 7 and 13 divide it as well as 1 and 91.
Example 2
Input: n = 1
Output:
falseExplanation: A prime must be greater than 1.
Example 3
Input: n = 2147483647
Output:
trueExplanation: No number from 2 to 2,147,483,646 divides it, so its only divisors are 1 and itself.
Check your understanding
Work out the answer for this input before you write any code.
n = 2
Constraints
1 ≤ n ≤ 1010
Clarifying questions
What you would ask an interviewer before writing any code.