630
The Gateway Arch is 630 feet tall and 630 feet wide.
- Even
- Composite
Where 630 fits
Why 630 is special
Its height and span are identical, which is unusual and deliberate. The curve is a weighted catenary — the shape a hanging chain takes, inverted — chosen because it carries its own weight in pure compression.
630 is part of
Factors & digit properties
- Divisors (24)
- 1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 30, 35, 42, 45, 63, 70, 90, 105, 126, 210, 315, 630
- Prime factorisation
- 2 × 3^2 × 5 × 7
- Digit sum
- 9
- Digital root
- 9
Representations
- Decimal
- 630
- Scientific notation
- 6.300 × 10^2
Roman numerals
D C X X X
Binary
1 0 0 1 1 1 0 1 1 0
1 × 512 + 0 × 256 + 0 × 128 + 1 × 64 + 1 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 630
Octal
1 1 6 6
1 × 512 + 1 × 64 + 6 × 8 + 6 × 1 = 630
Hexadecimal
2 7 6
2 × 256 + 7 × 16 + 6 × 1 = 630
Read as powers of two: 512 + 64 + 32 + 16 + 4 + 2 = 630.
In historical numeral systems
Egyptian
6 coils of rope, 3 hobbles
6 × 100 + 3 × 10 = 630. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge (sixties place), 3 corner wedges (units place)
10 × 60 + 30 = 630. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
chi, then lambda, marked as a numeral
chi-lambda + keraia
chi + lambda 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 resh, then lamed
tav-resh-lamed
tav (400) + resh (200) + lamed (30) = 630, 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
- Triangular number
- Abundant number
- Hexagonal number
- Harshad (Niven) number
Related numbers & connections
The Gateway Arch stands in pure compression as an inverted catenary; the Eiffel Tower is a lattice carrying load in tension and compression together. Two different answers to holding up a tall structure.
View 324 →Other connections
- contrasts with324
why?
Strength 0.50, confidence "high".
Technology & computing
The Gateway Arch is a weighted catenary, the inverted form of a freely hanging chain. That curve puts the structure entirely in compression, which is why it needs no internal bracing.
DocumentedTechnology & computingGeography: St Louis, United States
Common questions
Is 630 a prime number?
No, 630 is not prime.
What are the factors of 630?
The factors of 630 are 1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 30, 35, 42, 45, 63, 70, 90, 105, 126, 210, 315, 630.
What is 630 in Roman numerals?
630 in Roman numerals is DCXXX.
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