00000000599536830000000059953683 is a 16 character string. The last character is a check character for that string, calculated according ISO 7064 MOD 11-2. The string could be an ISNI according to ISO 27729.
In print an ISNI can be written as four blocks of four characters, in such cases often preceded by the string 'ISNI': ISNI 0000 0000 5995 3683
ISNI based link
- Wikimedia ("ISNI"=0000 0000 5995 3683)
ISNI based matchVIAF