Euler 12需要优化

我已经解决了 euler problem 12 ,但它需要一些优化。我在euler论坛上读过,但它并没有帮助我优化它。然而,我已经设法找到了解决方案,我只需要加快速度。目前运行需要4分钟。这是我的代码:

import time

def nthtriangle(n):
    return (n * (n + 1)) / 2

def numberofnfactors(n):
    count = 0
    if n==1:
        return 1
    for i in range(1, 1 + int(n ** 0.5)):
        if n % i == 0:
            count += 2
    return count


def FirstTriangleNumberWithoverxdivisors(divisors):
    found = False
    counter = 1
    while not found:
        print(int(nthtriangle(counter)), "                   ", numberofnfactors(nthtriangle(counter)))
        if numberofnfactors(nthtriangle(counter)) > divisors:
            print(" first triangle with over ",divisors, " divisors is ", int(nthtriangle(counter)))
            found = True
            break
        counter += 1

start_time = time.time()
FirstTriangleNumberWithoverxdivisors(500)
print("My program took", time.time() - start_time, "to run")