8253
The 8253 programmable interval timer generated the PC's clock ticks.
- Odd
- Composite
Where 8253 fits
Why 8253 is special
Its 1.19 MHz base frequency is an artefact of dividing the colour television subcarrier used in the original IBM PC design, which is why PC timing had an unrelated broadcast standard buried inside it.
Factors & digit properties
- Divisors (12)
- 1, 3, 7, 9, 21, 63, 131, 393, 917, 1179, 2751, 8253
- Prime factorisation
- 3^2 × 7 × 131
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 8253
- Binary
- 10000000111101
- Octal
- 20075
- Hexadecimal
- 203d
- Scientific notation
- 8.253 × 10^3
Other mathematical patterns
- Deficient number
- Lucky number (mathematical sieve)
Related numbers & connections
The 6845 generated video timing and the 8253 system timing, and both derived their frequencies from television standards through shared crystals.
View 6845 →Technology & computing
The 8253 ran at roughly 1.19 MHz because that figure came from dividing the NTSC colour subcarrier, chosen so one crystal could serve both timing and video. Broadcast television shaped how PCs counted time.
DocumentedTechnology & computing
Common questions
Is 8253 a prime number?
No, 8253 is not prime.
What are the factors of 8253?
The factors of 8253 are 1, 3, 7, 9, 21, 63, 131, 393, 917, 1179, 2751, 8253.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 3 August 2026