  We have calculated on the computer the sum $\bar{\BB}_M$ of reciprocals of
all 47 known Mersenne primes with the accuracy of over 12000000 decimal digits.
Next we developed $\bar{\BB}_M$ into the continued fraction and calculated
geometrical means of the partial denominators of the continued fraction
expansion of $\bar{\BB}_M$. We get values converging to the Khinchin's
constant. Next we calculated the $n$-th square roots of the denominators of the
$n$-th convergents of these continued fractions obtaining values approaching
the Khinchin-L{\`e}vy constant. These two results suggests that the sum of
reciprocals of all Mersenne primes is irrational, supporting the common believe
that there is an infinity of the Mersenne primes. For comparison we have done
the same procedures with slightly modified set of 47 numbers obtaining quite
different results. Next we investigated the continued fraction whose partial
quotients are Mersenne primes and we argue that it should be transcendental.
