390
The Class 390 Pendolino tilts into curves.
- Even
- Composite
Where 390 fits
Why 390 is special
Tilting let faster trains use a Victorian alignment without rebuilding it, which is cheaper than straightening a railway and produces most of the same journey time.
Factors & digit properties
- Divisors (16)
- 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195, 390
- Prime factorisation
- 2 × 3 × 5 × 13
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 390
- Scientific notation
- 3.900 × 10^2
Roman numerals
C C C X C
CCCXC uses the subtractive pair XC: ten before a hundred — a hundred minus ten.
Binary
1 1 0 0 0 0 1 1 0
1 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 390
Octal
6 0 6
6 × 64 + 0 × 8 + 6 × 1 = 390
Hexadecimal
1 8 6
1 × 256 + 8 × 16 + 6 × 1 = 390
Read as powers of two: 256 + 128 + 4 + 2 = 390.
In historical numeral systems
Egyptian
3 coils of rope, 9 hobbles
3 × 100 + 9 × 10 = 390. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
6 vertical wedges (sixties place), 3 corner wedges (units place)
6 × 60 + 30 = 390. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
tau, then koppa, marked as a numeral
tau-koppa + keraia
tau + koppa written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
shin, then tsadi
shin-tsadi
shin (300) + tsadi (90) = 390, written in descending order.
Maya
3 bars + 4 dots (upper, twenties place) over 2 bars (lower, units place)
19 × 20 + 10 = 390. 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
- Abundant number
Related numbers & connections
Tilting let the Pendolino take a Victorian alignment at speed, where the earlier fleet needed the route straightened.
View 225 →Other connections
- contrasts with225
why?
Strength 0.50, confidence "high".
Technology & computing
The British Rail Class 390 uses active tilt to permit higher speeds through curves on the West Coast Main Line without realignment of the existing route.
DocumentedTechnology & computingGeography: United KingdomPeriod: 2002–
Common questions
Is 390 a prime number?
No, 390 is not prime.
What are the factors of 390?
The factors of 390 are 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195, 390.
What is 390 in Roman numerals?
390 in Roman numerals is CCCXC. XC is subtractive: ten before a hundred — a hundred minus ten. Written additively it would be CCCLXXXX, which Roman inscriptions used freely — the strict subtractive form is a later convention.
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