556
The 556 is a dual 555 timer.
- Even
- Composite
Where 556 fits
Why 556 is special
Two independent timers in one package are how a single chip generates both a clock and a delay, which many 555 circuits need at once.
556 is part of
Factors & digit properties
- Divisors (6)
- 1, 2, 4, 139, 278, 556
- Prime factorisation
- 2^2 × 139
- Digit sum
- 16
- Digital root
- 7
Representations
- Decimal
- 556
- Scientific notation
- 5.560 × 10^2
Roman numerals
D L V I
Binary
1 0 0 0 1 0 1 1 0 0
1 × 512 + 0 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 0 × 1 = 556
Octal
1 0 5 4
1 × 512 + 0 × 64 + 5 × 8 + 4 × 1 = 556
Hexadecimal
2 2 c
2 × 256 + 2 × 16 + c × 1 = 556
Read as powers of two: 512 + 32 + 8 + 4 = 556.
In historical numeral systems
Egyptian
5 coils of rope, 5 hobbles, 6 strokes
5 × 100 + 5 × 10 + 6 × 1 = 556. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
9 vertical wedges (sixties place), 1 corner wedge + 6 vertical wedges (units place)
9 × 60 + 16 = 556. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
phi, then nu, then stigma, marked as a numeral
phi-nu-stigma + keraia
phi + nu + stigma written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
tav, then qof, then nun, then vav
tav-qof-nun-vav
tav (400) + qof (100) + nun (50) + vav (6) = 556, written in descending order.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
- Happy number
Related numbers & connections
The 556 is two complete 555 timers sharing a package, for designs needing both a clock and a delay.
View 555 →Other connections
- developed from555
why?
Strength 0.50, confidence "high".
Technology & computing
The 556 contains two complete 555 timer circuits sharing supply and ground pins, used where a design requires two independent timing functions.
DocumentedTechnology & computingPeriod: 1970s–
Common questions
Is 556 a prime number?
No, 556 is not prime.
What are the factors of 556?
The factors of 556 are 1, 2, 4, 139, 278, 556.
What is 556 in Roman numerals?
556 in Roman numerals is DLVI.
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: 15 July 2026