2465
2,465 is a Carmichael number.
- Odd
- Composite
Where 2465 fits
Why 2465 is special
The first three — 561, 1105 and 2465 — are close enough together that a naive primality test fails on all of them within a few thousand numbers. That density near the start is why the risk is real rather than theoretical.
Factors & digit properties
- Divisors (8)
- 1, 5, 17, 29, 85, 145, 493, 2465
- Prime factorisation
- 5 × 17 × 29
- Digit sum
- 17
- Digital root
- 8
Representations
- Decimal
- 2465
- Scientific notation
- 2.465 × 10^3
Roman numerals
M M C D L X V
MMCDLXV uses the subtractive pair CD: a hundred before five hundred — five hundred minus a hundred.
Binary
1 0 0 1 1 0 1 0 0 0 0 1
1 × 2,048 + 0 × 1,024 + 0 × 512 + 1 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 2,465
Octal
4 6 4 1
4 × 512 + 6 × 64 + 4 × 8 + 1 × 1 = 2,465
Hexadecimal
9 a 1
9 × 256 + a × 16 + 1 × 1 = 2,465
Read as powers of two: 2,048 + 256 + 128 + 32 + 1 = 2,465.
In historical numeral systems
Egyptian
2 lotuses, 4 coils of rope, 6 hobbles, 5 strokes
2 × 1,000 + 4 × 100 + 6 × 10 + 5 × 1 = 2,465. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
4 corner wedges + 1 vertical wedge (sixties place), 5 vertical wedges (units place)
41 × 60 + 5 = 2465. Places are separated by a space on the tablet, with the higher place written first.
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
- Harshad (Niven) number
Mathematics
561, 1,105 and 2,465 are all Carmichael numbers below 2,500. A probabilistic primality test that checks few bases will accept all three, which is why cryptographic implementations test many.
DocumentedMathematics
Common questions
Is 2465 a prime number?
No, 2465 is not prime.
What are the factors of 2465?
The factors of 2465 are 1, 5, 17, 29, 85, 145, 493, 2465.
What is 2465 in Roman numerals?
2465 in Roman numerals is MMCDLXV. CD is subtractive: a hundred before five hundred — five hundred minus a hundred. Written additively it would be MMCCCCLXV, 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