Hackerrank Sum vs XoR

I’m in the process of improving my coding style and performance hence I decided to delve into bit manipulation on Hackerrank. I thought the question was straight forward but on large input, my solution’s performance declines. How do I improve it? Any smart tricks to solve the below question is welcome as well.

Below is the question

Given an integer, $n$ , find each $x$ such that:

$0 leq x leq n$

$n + x = n oplus x$

where $oplus$ denotes the bitwise XOR operator. Then print an
integer denoting the total number of $x$ ‘s satisfying the criteria
above.

Input Format

A single integer, $n$ .

Constraints

$0 leq n leq 10 ^ {15}$

Subtasks

$0 leq n leq 100$ for $60%$ of the maximum score

Output Format

Print the total number of integer $x$ ‘s satisfying both of the
conditions specified above.

Sample Input 0

5

Sample Output 0

2

Explanation 0

For $n = 5$ , the $x$ values $0$ and $2$ satisfy the
conditions:

Thus, we print $2$ as our answer.

Here is my code

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {
     static int SumVsXoR(long number)
    {
        int count =0;
        long j = 0;
        while (j <= number)
        {           
            if(j + number == (j^number)){               
                count++;                
            }
            j++;
        }
        return count;
    }

    static void Main(String[] args) {
        long n = Convert.ToInt64(Console.ReadLine());
        Console.WriteLine(SumVsXoR(n));
    }
}

Let’s notice that
$n + x = n oplus x$ is true
when and only when
$n + x = n vee x$ is true

This is because
$n + x geq n vee x = n oplus x + n wedge x$.

Where:

• $vee$ – bitwise OR
• $wedge$ – bitwise AND

So we just need to calculate the number of zero bits in the $n$.
Let’s calculate the nonzero bits:

private static int NumberOfSetBits(ulong i)
{
    i = i - ((i >> 1) & 0x5555555555555555UL);
    i = (i & 0x3333333333333333UL) + ((i >> 2) & 0x3333333333333333UL);
    return (int)(unchecked(((i + (i >> 4)) & 0xF0F0F0F0F0F0F0FUL) * 0x101010101010101UL) >> 56);
}

The method above was copy-pasted from this answer: stackoverflow.com

Then rewrite the SumVsXoR method:

private static int SumVsXoR(ulong number)
{
    int numberOfBits = (int)Math.Log(number, 2) + 1;
    return 1 << (numberOfBits - NumberOfSetBits(number));
}