*18,446,744,073,709,551,615 redirects here, which is similarly 2*^{64}− 1

9223372036854775807 | |
---|---|

Cardinal | nine quintillion two hundred twenty-three quadrillion three hundred seventy-two trillion thirty-six billion eight hundred fifty-four million seven hundred seventy-five thousand eight hundred seven |

Ordinal | 9223372036854775807th (nine quintillion two hundred twenty-three quadrillion three hundred seventy-two trillion thirty-six billion eight hundred fifty-four million seven hundred seventy-five thousand eight hundred seventh) |

Factorization | 7^{2} × 73 × 127 × 337 × 92737 × 649657 |

Greek numeral | ͵εωζ´ |

Roman numeral |

The number **9,223,372,036,854,775,807** is the integer equal to 2^{63} − 1. Its prime factorization is 7^{2} · 73 · 127 · 337 · 92737 · 649657, which is equal to Φ_{3}(2) · Φ_{7}(2) · Φ_{9}(2) · Φ_{21}(2) · Φ_{63}(2).

The number 9,223,372,036,854,775,807, equivalent to the hexadecimal value 7FFF,FFFF,FFFF,FFFF_{16}, 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 (`long`

, `long long int`

, or `bigint`

) 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]}^{(p130)}). 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 2^{63}−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 30828 (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 and C++ this is available as the `long long`

data type signed or unsigned), in C#, `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 2^{64} − 1.

**^**"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***^**AMD Corporation (December 2016). "Volume 2: System Programming" (PDF).*AMD64 Architecture Programmer's Manual*. AMD Corporation.**^**"time_t"*cplusplus.com***^**Thulin, Anders (6 April 2013). "Interpretation of NTFS Timestamps".*Forensic Focus*. Retrieved 23 July 2019.**^**long (C# Reference) | Microsoft Docs**^**Int64 Struct (System) | Microsoft Docs