170
170 is the highest possible finish in darts.
- Even
- Composite
Why 170 is special
It is three darts: treble twenty, treble twenty, bullseye. Anything above 170 cannot be finished in three darts because the double required to win must land exactly, which is why 170 rather than 180 is the number commentators call the big fish.
Factors & digit properties
- Divisors (8)
- 1, 2, 5, 10, 17, 34, 85, 170
- Prime factorisation
- 2 × 5 × 17
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 170
- Scientific notation
- 1.700 × 10^2
Roman numerals
C L X X
Binary
1 0 1 0 1 0 1 0
1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 170
Octal
2 5 2
2 × 64 + 5 × 8 + 2 × 1 = 170
Hexadecimal
a a
a × 16 + a × 1 = 170
Read as powers of two: 128 + 32 + 8 + 2 = 170.
In historical numeral systems
Egyptian
1 coil of rope, 7 hobbles
1 × 100 + 7 × 10 = 170. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 vertical wedges (sixties place), 5 corner wedges (units place)
2 × 60 + 50 = 170. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
rho, then omicron, marked as a numeral
rho-omicron + keraia
rho + omicron written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
qof, then ayin
qof-ayin
qof (100) + ayin (70) = 170, written in descending order.
Maya
1 bar + 3 dots (upper, twenties place) over 2 bars (lower, units place)
8 × 20 + 10 = 170. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
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
Sport
180 is the highest score from three darts, but a leg must end on a double, so the highest possible checkout is 170 — treble twenty, treble twenty, bullseye. The distinction between scoring and finishing is what makes darts scoring counterintuitive to newcomers.
DocumentedSport
Common questions
Is 170 a prime number?
No, 170 is not prime.
What are the factors of 170?
The factors of 170 are 1, 2, 5, 10, 17, 34, 85, 170.
What is 170 in Roman numerals?
170 in Roman numerals is CLXX.
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