The (structured) output of the Nmap script "ssl-cert" reports a "representation" of some integers (at least, the exponent and modulus of RSA keys), rather than their actual values:
$ nmap -n -PS443 -p 443 --script=ssl-cert -oX - www.nmap.org | \
> grep -E '^<elem key="(modulus|exponent)">'
<elem key="exponent">BIGNUM: 0xXXXXXXXXXXXX</elem>
<elem key="modulus">BIGNUM: 0xXXXXXXXXXXXX</elem>