def sum_of_factors(num):
    # Sum of factors of num
    sum_factors = 0
    for i in range(1, int(num**0.5) + 1):
        if num % i == 0:
            sum_factors += i
            if i != num // i:
                sum_factors += num // i
    return sum_factors

def maxSubsetSum(arr):
    # Apply sum_of_factors to each element in arr
    return [sum_of_factors(num) for num in arr]

# Example usage:
arr = [12]  # Example input from the image
result = maxSubsetSum(arr)
print(result)  # Expected output: [28]