822
RFC 822 defined the format of an email message itself.
- Even
- Composite
Where 822 fits
Why 822 is special
Its header syntax — From, To, Subject, Date — is why a message written in 1982 still parses correctly in a mail client written today.
Factors & digit properties
- Divisors (8)
- 1, 2, 3, 6, 137, 274, 411, 822
- Prime factorisation
- 2 × 3 × 137
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 822
- Scientific notation
- 8.220 × 10^2
Roman numerals
D C C C X X I I
Binary
1 1 0 0 1 1 0 1 1 0
1 × 512 + 1 × 256 + 0 × 128 + 0 × 64 + 1 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 822
Octal
1 4 6 6
1 × 512 + 4 × 64 + 6 × 8 + 6 × 1 = 822
Hexadecimal
3 3 6
3 × 256 + 3 × 16 + 6 × 1 = 822
Read as powers of two: 512 + 256 + 32 + 16 + 4 + 2 = 822.
In historical numeral systems
Egyptian
8 coils of rope, 2 hobbles, 2 strokes
8 × 100 + 2 × 10 + 2 × 1 = 822. 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 + 2 vertical wedges (units place)
13 × 60 + 42 = 822. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
omega, then kappa, then beta, marked as a numeral
omega-kappa-beta + keraia
omega + kappa + beta 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 bet
tav-tav-kaf-bet
tav (400) + tav (400) + kaf (20) + bet (2) = 822, 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
- Abundant number
Related numbers & connections
MIME extended the RFC 822 message so that a format guaranteeing only seven-bit text could carry images and binary attachments.
View 2045 →Technology & computing
RFC 822 specifies the structure of a text message: a block of colon-separated headers, a blank line, then the body. The same shape underlies HTTP and MIME.
DocumentedTechnology & computingGeography: International — IETFPeriod: 1982
Common questions
Is 822 a prime number?
No, 822 is not prime.
What are the factors of 822?
The factors of 822 are 1, 2, 3, 6, 137, 274, 411, 822.
What is 822 in Roman numerals?
822 in Roman numerals is DCCCXXII.
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