Using an array in a struct with pthread_join

Question

I need some help with this. I am making a threaded factor program. Takes arguments from the command line, finds the prime factors and outputs them.

However, my problem is that if I have multiple arguments being passed in (e.x. 20 15 10 5), all of my outputs use the same values as the first argument being passed in.

example output:

20: 2 2 5
15: 2 2 5
10: 2 2 5
5: 2 2 5

Could any of you get a second pair of eyes on this and see why I am printing the same thing for different threads?

My intuition says that it is because I am using one static array in my struct, and each time a new thread uses it, it overwrites data already there from previous calculations. I could be wrong.

struct prime_struct {
    int array[100];
    int limit;
};

void* prime_factor(void* number)
{
    int i, count = 0; // count is used to increment through array
    int n = *((int*)number);
    int limit = *((int*)number);

    struct prime_struct *arg_struct = (struct prime_struct*) number; 

    while (n % 2 == 0)
    {
        n = n / 2; // Halve number
        arg_struct->array[count] = 2; // Two is a factor store it in position 1 of array
        count++;            
    }
    for (i = 3; i <= limit; i = i + 2)
    {
        while(n % i == 0)
        {
            n = n / i;
            arg_struct->array[count] = i;
            count++;
        }
    }

    arg_struct->limit = count;
    pthread_exit(0);
}

int main(int argc, char* argv[])
{
    if (argc < 2) 
    {
        printf("Please enter an integer value.");
        exit(-1);
    }

    int i, j, k, m;
    int args = argc - 1;
    int number[args];

    pthread_t tids[args]; // pthread_t tid; // Thread id
    // struct prime_struct array_struct[args];
    struct prime_struct *array_struct = (struct prime_struct*) number; 

    for (i = 0; i < args; i++)
    {
        number[i] = atoi(argv[i + 1]);

        pthread_attr_t attr; // Create attributes
        pthread_attr_init(&attr);
        pthread_create(&tids[i], &attr, prime_factor, &number[i]);// &array_struct[i + 1]); // plus one because I want the first number not the ./assn3
    }

    for (j = 0; j < args; j++)
    {   
        // Wait until thread is done, get value back from child and print factors
        pthread_join(tids[j], NULL);
    }
    int limit = array_struct->limit;
        for (k = 0; k < args; k++) // print array
        {
            printf("%s: ", argv[k + 1]);
            for (m = 0; m < limit; m++)
            {
                printf("%d ", array_struct->array[m]);
            }
            printf("\n");
        }
    return 0;
}

Example output for an input of 20 would be

20: 2 2 5