301
301 is the HTTP status code for a permanent redirect — the resource has moved for good.
- Odd
- Composite
Where 301 fits
Why 301 is special
301 is the code that moves the web without breaking it. It tells browsers and search engines that a URL has changed permanently, so bookmarks follow and accumulated search ranking transfers to the new address. Getting it wrong — using a temporary 302 for a permanent move — is one of the classic ways a site loses its search visibility during a redesign.
Not just a mathematical number
301is also used in ways where ordinary arithmetic doesn't apply — each listed below with what genuinely does and doesn't follow from it.
- Mathematical number
A genuine quantity — its mathematical properties (prime, square, factors, and so on) are real facts about it.
A genuine quantity that ordinary arithmetic applies to — it can be prime, even, a perfect square, added to another number meaningfully, and so on.
- Code
Also used as a code — HTTP status codes.
An assigned identifier from a fixed registry or standard — its digits don't represent an amount, and arithmetic on it is meaningless (HTTP status 404 + 1 is not a 'better' status; it's a different, unrelated code).
301 is part of
Factors & digit properties
- Divisors (4)
- 1, 7, 43, 301
- Prime factorisation
- 7 × 43
- Digit sum
- 4
- Digital root
- 4
Representations
- Decimal
- 301
- Binary
- 100101101
- Octal
- 455
- Hexadecimal
- 12d
- Roman numeral
- CCCI
- Scientific notation
- 3.010 × 10^2
Other mathematical patterns
- Deficient number
- Happy number
- Semiprime
Related numbers & connections
301 marks a permanent move and transfers accumulated search authority to the new URL.
The single most consequential choice in redirect configuration. 301 says the move is permanent and passes search authority on; 302 says it is temporary and keeps the original canonical. Using 302 for a permanent migration is a documented way to lose search traffic.
View 302 →Technology & computing
A 301 transfers a URL's accumulated search authority to its new address; a 302 does not, because it says the move is temporary. Site migrations that used 302 by mistake are a well-documented way to lose search traffic overnight, and the fix is usually a one-character change in a configuration file.
DocumentedTechnology & computing
Common questions
Is 301 a prime number?
No, 301 is not prime.
What are the factors of 301?
The factors of 301 are 1, 7, 43, 301.
What is 301 in Roman numerals?
301 in Roman numerals is CCCI.
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: 3 August 2026