Nodejs Number Prime Number Check primeFactors()

Method Source Code

"use strict";//from   w w  w. j a  va2s.com

var i, j, triangleNumber;

Number.prototype.primeFactors = function() {
  var v, i;

  v = null;

  for (i = 2; i < this - 1; i += 1) {
    if (this % i === 0) {
      v = i;

      break;
    }
  }

  if (v) {
    return [v].concat(Math.floor(this / v).primeFactors());
  } else {
    return [this];
  }
};

Number.prototype.numberOfDivisors = function() {
  var factorGroups;

  factorGroups = {};

  this.primeFactors().forEach(function(primeFactor) {
    factorGroups[primeFactor] = (factorGroups[primeFactor] || 1) + 1;
  });

  return Object.keys(factorGroups).reduce(function(previousValue, key) {
    return previousValue * factorGroups[key];
  }, 1);
};

i = 2;

triangleNumber = 1;

while (triangleNumber.numberOfDivisors() <= 500) {
  triangleNumber = 0;

  for (j = 1; j <= i; j += 1) {
    triangleNumber += j;
  }

  i += 1;
}

console.log(triangleNumber);

Related

1. primeFactorization()

   Number.prototype.primeFactorization = function () {
       var ans = [];
       var primes = [];
       var temp = this;
       for (let i = 2; i <= temp / 2; i++) {
           if (i.divisors().length == 2) {
               primes.push(i);
       for (let i = 0; i < primes.length; i++) {
           while (i.isDivisor(temp)) {
               ans.push(primes[i]);
               temp = temp / primes[i];
       return ans;
   

2. primeFactorization()

   Number.prototype.primeFactorization = function () {
       var ans = [];
       var primes = [];
       var temp = this;
       for (let i = 2; i <= temp / 2; i++) {
           if (i.divisors().length == 2) {
               primes.push(i);
       for (let i = 0; i < primes.length; i++) {
           while (temp.isDevisor(primes[i])) {
               ans.push(primes[i]);
               temp = temp / primes[i];
       return ans;
   

3. primeFactorization()

   Number.prototype.primeFactorization = function (){
       console.log("prime aangekomen");
       var ans = [];
       var primes = [];
       var temp = this;
       for(let i = 2; i<temp/2; i++){
           if(i.divisors().length == 2){
               primes.push(i);
       for (let i =0; i<primes.length; i++){
               while(temp.isDivisor(primes[i])){
                   ans.push(primes[i]);
                   temp = temp/primes[i];
       return ans;
   };
   

4. primeFactorization()

   Number.prototype.primeFactorization = function () {
       "use strict";
       var ans = [];
       var primes = [];
       var temp = this;
       for (let i = 2; i <= this / 2; i += 1) {
           if (i.divisors().length == 2) {
               primes.push(i);
       for (let i = 0; i < primes.length; i += 1) {
           while (temp.isDivisor(primes[i])) {
               ans.push(primes[i]);
               temp = temp / primes[i];
       return ans;
   };
   

5. primeFactors()

   "use strict";
   Number.prototype.primeFactors = function() {
     var v, i;
     v = null;
     for (i = 2; i < this - 1; i += 1) {
       if (this % i === 0) {
         v = i;
         break;
     if (v) {
       return [v].concat(Math.floor(this / v).primeFactors());
     } else {
       return [this];
   };
   console.log(Math.max.apply(null, (600851475143).primeFactors()));
   

6. primeFactors()

   Number.prototype.primeFactors = function() {
     var number = this.valueOf();
     var primeFactors = [];
     isPrime = function(primeCandidate) {
       var p = 2;
       var top = Math.floor(Math.sqrt(primeCandidate));
       while(p<=top){
         if(primeCandidate%p === 0){ return false; }
         p++;
   ...
   

7. primeFactors()

   "use strict";
   var i, primeFactorLists;
   Number.prototype.primeFactors = function() {
     var v, i;
     v = null;
     for (i = 2; i < this - 1; i += 1) {
       if (this % i === 0) {
         v = i;
         break;
   ...
   

8. sumPrimes(num)

   function sumPrimes(num) {
     var primes = [];
     for (var i = 2; i <= num; i++) {
       var notPrime = false;
       for (var current = 2; current <= (i - 1); current++) {
           if (i % current === 0) {
             notPrime = true;
       if (notPrime === false) 
         primes.push(i);
     var sum = primes.reduce(function(pv, cv) { 
                 return pv + cv;
               });
     return sum;
   sumPrimes(10);
   

9. sumPrimes(num)

   function sumPrimes(num) {
     function isPrime(number) {
       for (var i = 2; i < number; i++) {
         if (number % i === 0) {
           return false;
       return true;
     var sum = 0;
     for (var j = 2; j <= num; j++) {
       if (isPrime(j)) {
         sum += j;
     return sum;
   sumPrimes(10);