odd, prime · 401st positive integer
The number 401
401 is an odd prime number. It is the 401st positive integer.
Quick reference
| Prime factorization | 401 (prime) |
| Divisors | 1, 401 |
| Binary | 110010001 |
| Hexadecimal | 0x191 |
| Roman numeral | CDI |
| Digit sum | 5 |
| Properties | odd, prime |
Reading 401 in NumGrid context
401 is one of the data points covered by this site’s integer properties and number-guessing puzzles dataset. The detail above comes directly from classical number theory plus NumGrid solver-derived puzzle statistics; the context that follows situates the headline numbers against the broader distribution across positive integers within the NumGrid target pool.
The methodology behind every numeric value on this page is publicly documented on the classical number theory plus NumGrid solver-derived puzzle statistics portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for 401 is typically a peer within positive integers within the NumGrid target pool with similar size, similar exposure, or similar geography — not the national-level summary alone.
Frequently asked
Is 401 a prime number?
Yes. 401 is prime — its only divisors are 1 and itself.
What are the factors of 401?
The factors (divisors) of 401 are 1, 401.
What is 401 in binary?
401 in binary is 110010001. In hexadecimal it's 191.
What is 401 as a Roman numeral?
401 in Roman numerals is CDI.
What's the digit sum of 401?
Adding the digits of 401: 4 + 0 + 1 = 5.