class Integer
  def divis_by?(n)
    if n != 0
      self.to_f / n == (self.to_f / n).to_i
    end
  end

  def factors
    f = [1]
    for i in 2..self-1
      f.push i if self.divis_by?(i)
    end
    f.push self
    f
  end
end



  i = 1
  add = 2
  while i.factors.length <= 500
    puts "#{i} #{i.factors.length}"
    i += add
    add += 1
  end
  puts "First triangle number with over 500 factors: #{i}"