Section 47. Except as reserved to the stockholders pursuant to section fifty-four, the business of every corporation shall be managed by a board of directors. The number of directors shall be fixed by or determined in the manner provided in the by-laws, but shall be not less than three, except that whenever there shall be only two stockholders the number of directors shall be not less than two and whenever there shall be only one stockholder or prior to the issuance of any stock, there shall be at least one director. Except as otherwise provided in sections fifty and fifty-two or in the articles of organization, the directors shall be elected at the annual meeting of the stockholders by such stockholders as have the right to vote thereon. The board of directors may be enlarged by the stockholders at any meeting or, if authorized by the by-laws, by vote of a majority of the directors then in office. Any elections of directors by stockholders shall be by ballot if so requested by any stockholder entitled to vote thereon. Unless required by the by-laws, no director need be a stockholder.