825
Alloy 825 is a nickel-iron-chromium alloy.
- Odd
- Composite
Where 825 fits
Why 825 is special
It was developed specifically for sulphuric and phosphoric acid service, where stainless steel fails and a full nickel alloy is not affordable.
Factors & digit properties
- Divisors (12)
- 1, 3, 5, 11, 15, 25, 33, 55, 75, 165, 275, 825
- Prime factorisation
- 3 × 5^2 × 11
- Digit sum
- 15
- Digital root
- 6
Representations
- Decimal
- 825
- Scientific notation
- 8.250 × 10^2
Roman numerals
D C C C X X V
Binary
1 1 0 0 1 1 1 0 0 1
1 × 512 + 1 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 825
Octal
1 4 7 1
1 × 512 + 4 × 64 + 7 × 8 + 1 × 1 = 825
Hexadecimal
3 3 9
3 × 256 + 3 × 16 + 9 × 1 = 825
Read as powers of two: 512 + 256 + 32 + 16 + 8 + 1 = 825.
In historical numeral systems
Egyptian
8 coils of rope, 2 hobbles, 5 strokes
8 × 100 + 2 × 10 + 5 × 1 = 825. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 3 vertical wedges (sixties place), 4 corner wedges + 5 vertical wedges (units place)
13 × 60 + 45 = 825. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
omega, then kappa, then epsilon, marked as a numeral
omega-kappa-epsilon + keraia
omega + kappa + epsilon 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 tav, then kaf, then he
tav-tav-kaf-he
tav (400) + tav (400) + kaf (20) + he (5) = 825, 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
- Deficient number
- Harshad (Niven) number
Related numbers & connections
Both were developed for acid service, trading nickel content against cost.
View 904 →Other connections
- developed from904
why?
Strength 0.50, confidence "high".
Technology & computing
Alloy 825 contains nickel, iron, chromium, molybdenum and copper, developed for resistance to reducing acids at lower cost than higher nickel alloys.
DocumentedTechnology & computingGeography: International — AISI, SAE and Aluminium Association designations
Common questions
Is 825 a prime number?
No, 825 is not prime.
What are the factors of 825?
The factors of 825 are 1, 3, 5, 11, 15, 25, 33, 55, 75, 165, 275, 825.
What is 825 in Roman numerals?
825 in Roman numerals is DCCCXXV.
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