The following data has been collected about Keller Company's stockholders' equity accounts: Common stock $10 par value 16,000 shares authorized and 8,000 shares issued, 2,400 shares outstanding $80,000 Paid-in-capital in excess of par value, common stock 46,000 Retained earnings 21,000 Treasury stock 26,640 Assuming the treasury shares were all purchased at the same price, the number of shares of treasury stock is: