In mathematical logic, a Meertens number is an integer that is its own Gödel number.
The Gödel encoding of a decimal number with n digits is the product of the first n primes raised to the values of their corresponding digits in the sequence.
The only Meertens number that has been found is 81312000 = 28315371112130170190.
It was "given" to Lambert Meertens by Richard S. Bird as a present during the celebration of his 25 years at the CWI, Amsterdam. [1]