// Function that returns true if n // is prime else returns false function isPrime(n) { // Corner cases if (n <= 1) return false; if (n <= 3) return true; // This is checked so that we can skip // middle five numbers in below loop if (n%2 == 0 || n%3 == 0) return false; for (let i=5; i*i<=n; i=i+6) if (n%i == 0 || n%(i+2) == 0) return false; return true; }