function isPrime(num) { if (num <= 1) return false; if (num <= 3) return true; if (num % 2 === 0 || num % 3 === 0) return false; const sqrt = Math.sqrt(num); for (let i = 5; i <= sqrt; i += 6) { if (num % i === 0 || num % (i + 2) === 0) { return false; } } return true; } console.log(isPrime(1070)); console.log(isPrime(1453)); console.log(isPrime(1071)); console.log(isPrime(4831)); console.log(isPrime(7877));