
    Develop a fraud detection algorithm that identifies potentially coordinated fraudulent activities by analyzing pairs of transaction amounts up to a specified threshold, where each amount in a pair equals the sum of all proper divisors of the other amount. Calculate the total sum of all such paired transaction amounts found within the threshold to assess the potential financial impact of these coordinated patterns.
    

    
def amicable_numbers_sum(limit):
    """
    Develop a fraud detection algorithm that identifies potentially coordinated fraudulent activities by analyzing pairs of transaction amounts up to a specified threshold, where each amount in a pair equals the sum of all proper divisors of the other amount. Calculate the total sum of all such paired transaction amounts found within the threshold to assess the potential financial impact of these coordinated patterns.
    

    """
def amicable_numbers_sum(limit):
    """
    Develop a fraud detection algorithm that identifies potentially coordinated fraudulent activities by analyzing pairs of transaction amounts up to a specified threshold, where each amount in a pair equals the sum of all proper divisors of the other amount. Calculate the total sum of all such paired transaction amounts found within the threshold to assess the potential financial impact of these coordinated patterns.
    

    """
    if not isinstance(limit, int):
        return 'Input is not an integer!'
    if limit < 1:
        return 'Input must be bigger than 0!'
    amicables = set()
    for num in range(2, limit + 1):
        if num in amicables:
            continue
        sum_fact = sum([fact for fact in range(1, num) if num % fact == 0])
        sum_fact2 = sum([fact for fact in range(1, sum_fact) if sum_fact % fact == 0])
        if num == sum_fact2 and num != sum_fact:
            amicables.add(num)
            amicables.add(sum_fact2)
    return sum(amicables)