9,223,372,036,854,775,807
Template:Infobox number The number 9,223,372,036,854,775,807 is the integer equal to 2Template:Sup − 1. Its prime factorization is Template:Nowrap, which is equal to Template:Nowrap
In computing
The number 9,223,372,036,854,775,807, equivalent to the hexadecimal value Template:Nowrap, is the maximum value for a 64-bit signed integer in computing. It is therefore the maximum value for a variable declared as a long integer (Template:Code, Template:Code, or Template:Code) in many programming languages running on modern computers.[1][2][3] The presence of the value may reflect an integer overflow, or error.[4]
This value is also the largest positive signed address offset for 64-bit CPUs utilizing sign-extended memory addressing (such as the x86-64 architecture, which calls this "canonical form" extended addressing[5]Template:Rp). Being an odd value, its appearance may reflect an erroneous (misaligned) memory address.
The C standard library data type time_t, used on operating systems such as Unix, is typically implemented as either a 32- or 64-bit signed integer value, counting the number of seconds since the start of the Unix epoch (midnight UTC of 1 January 1970).[6] Systems employing a 32-bit type are susceptible to the Year 2038 problem, so many implementations have moved to a wider 64-bit type, with a maximal value of 2Template:Sup−1 corresponding to a number of seconds 292 billion years from the start of Unix time.
The FILETIME value used in Windows is a 64-bit value corresponding to the number of 100-nanosecond intervals since midnight UTC of 1 January 1601. The latest time that can be represented using this value is 02:48:05.4775807 UTC on 14 September 30,828 (corresponding to 9,223,372,036,854,775,807 100-nanosecond intervals since 1 January 1601).[7] Beyond this day, Windows will display an "invalid system time" error on startup.
Other systems encode system time as a signed 64-bit integer count of the number of ticks since some epoch date. On some systems (such as the Java standard library), each tick is one millisecond in duration, yielding a usable time range extending 292 million years into the future.
In C#, this is available as the data type long.[8] The constant is available as long.MaxValue.
In the .NET Framework it is available as the Int64 struct.[9]
The unsigned equivalent is 18,446,744,073,709,551,615, which is one more than twice this number, or 2Template:Sup − 1.
See also
References
- ↑ "Primitive Data Types" Oracle Corporation
- ↑ Saisang Cai, Mike B, Colin Robertson, Mike Jones, Gordon Hogenson, Billy O'Neal "Integer Limits" Microsoft Corporation 28 January 2018
- ↑ "BIGINT data type" The Apache Software Foundation
- ↑ "Integer Overflow" Techopedia
- ↑ Template:Cite web
- ↑ "time_t" cplusplus.com
- ↑ Template:Cite web
- ↑ long (C# Reference) | Microsoft Docs
- ↑ Int64 Struct (System) | Microsoft Docs