def triangle_nums():
    sum = 0
    n = 1
    while 1:
        sum += n
        yield sum
        n += 1

def factors(num):
    """ smallest1, biggest1, smallest2, biggest2 """
    n = 2
    while n*n <= num:
        if num % n == 0:
            yield n
            yield num / n
        n += 1

def main():
    for n in triangle_nums():
        if len(list(factors(n))) > 500:
            return n
        
print main()