format
uint64 - unsigned 64-bit integer
JSON Data Type: number, string.
The uint64 format represents an unsigned 64-bit integer, with the range 0 to 18446744073709551615.
Representation as a JSON string is recommended for values outside the 53-bit range (0 through 9007199254740991) as this avoids problems with recipients that parse JSON numbers into binary64 memory representation.