As per the latest available financial data, Citigroup's book value per share was $83.10 as of the end of the second quarter of 2021. In terms of the price-to-earnings (P/E) ratio, Citigroup's P/E ratio based on trailing twelve months earnings is 8.69, which is below the industry average. However, please note that these figures may have changed since the last financial report and you should always check for the latest financial data before making any investment decisions.