odd, prime · 421st positive integer
The number 421
421 is an odd prime number. It is the 421st positive integer.
Quick reference
| Prime factorization | 421 (prime) |
| Divisors | 1, 421 |
| Binary | 110100101 |
| Hexadecimal | 0x1A5 |
| Roman numeral | CDXXI |
| Digit sum | 7 |
| Properties | odd, prime |
Reading 421 in NumGrid context
For 421, the underlying data on this page comes from classical number theory plus NumGrid solver-derived puzzle statistics. The breakdown above is the federal record; the paragraphs below add the per-entity context that makes the headline numbers usable for a real decision rather than just a data lookup.
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 421 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 421 a prime number?
Yes. 421 is prime — its only divisors are 1 and itself.
What are the factors of 421?
The factors (divisors) of 421 are 1, 421.
What is 421 in binary?
421 in binary is 110100101. In hexadecimal it's 1A5.
What is 421 as a Roman numeral?
421 in Roman numerals is CDXXI.
What's the digit sum of 421?
Adding the digits of 421: 4 + 2 + 1 = 7.