The INTEGER data type holds an integer number in 64-bit
two’s complement form. This gives a range of values between -9223372036854775808
and +9223372036854775807.
Integer literals consist of an unquoted
string of digits only; that is, they contain neither a decimal point nor an
exponent; for example, 12345. They are of type INTEGER if they are small enough
to be represented as integers. Otherwise they are of type DECIMAL.
In
addition to this format, you can write integer literals in hexadecimal notation;
for example, 0x1234abcd. You can write the hexadecimal letters A to F, and
the "x" after the initial zero, in uppercase or lowercase. If you use
hexadecimal format, the number must be small enough to fit into an integer.
(That is, it cannot be a decimal.)