172
The Cessna 172 is the most-produced aircraft in history.
- Even
- Composite
Where 172 fits
Why 172 is special
More than 44,000 have been built since 1956, and it is still in production — a run no other aircraft type has matched.
Same number, different meanings
How 172 is understood across different contexts — never implying one meaning because of another.
- Mathematics
More than 44,000 have been built since 1956, and it is still in production — a run no other aircraft type has matched.
- Technology & computing
The Cessna 172 Skyhawk entered production in 1956 and has exceeded 44,000 units. Its high wing, fixed gear and benign handling made it the standard basic trainer across much of the world.
- Everyday life
E172 is iron oxides and hydroxides, used to colour confectionery and some pharmaceutical coatings in shades from yellow through red to black.
Factors & digit properties
- Divisors (6)
- 1, 2, 4, 43, 86, 172
- Prime factorisation
- 2^2 × 43
- Digit sum
- 10
- Digital root
- 1
Representations
- Decimal
- 172
- Scientific notation
- 1.720 × 10^2
Roman numerals
C L X X I I
Binary
1 0 1 0 1 1 0 0
1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 1 × 8 + 1 × 4 + 0 × 2 + 0 × 1 = 172
Octal
2 5 4
2 × 64 + 5 × 8 + 4 × 1 = 172
Hexadecimal
a c
a × 16 + c × 1 = 172
Read as powers of two: 128 + 32 + 8 + 4 = 172.
In historical numeral systems
Egyptian
1 coil of rope, 7 hobbles, 2 strokes
1 × 100 + 7 × 10 + 2 × 1 = 172. 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 + 2 vertical wedges (units place)
2 × 60 + 52 = 172. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
rho, then omicron, then beta, marked as a numeral
rho-omicron-beta + keraia
rho + omicron + beta 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, then bet
qof-ayin-bet
qof (100) + ayin (70) + bet (2) = 172, written in descending order.
Maya
1 bar + 3 dots (upper, twenties place) over 2 bars + 2 dots (lower, units place)
8 × 20 + 12 = 172. 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
Related numbers & connections
The 152 exists because the four-seat 172 was more aircraft than a student pilot needs.
View 152 →Technology & computing
The Cessna 172 Skyhawk entered production in 1956 and has exceeded 44,000 units. Its high wing, fixed gear and benign handling made it the standard basic trainer across much of the world.
DocumentedTechnology & computingGeography: United States, flown worldwidePeriod: 1956–
Everyday life
E172 is iron oxides and hydroxides, used to colour confectionery and some pharmaceutical coatings in shades from yellow through red to black.
DocumentedEveryday lifeGeography: European Union and states adopting the E number systemPeriod: 1962–
Common questions
Is 172 a prime number?
No, 172 is not prime.
What are the factors of 172?
The factors of 172 are 1, 2, 4, 43, 86, 172.
What is 172 in Roman numerals?
172 in Roman numerals is CLXXII.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026