odd, composite, triangular · 861st positive integer
The number 861
861 is an odd composite number. It is the 861st positive integer.
Quick reference
| Prime factorization | 3 × 7 × 41 |
| Divisors | 1, 3, 7, 21, 41, 123, 287, 861 |
| Binary | 1101011101 |
| Hexadecimal | 0x35D |
| Roman numeral | DCCCLXI |
| Digit sum | 15 |
| Properties | odd, composite, triangular |
Reading 861 in NumGrid context
The 861 record above pulls directly from classical number theory plus NumGrid solver-derived puzzle statistics. What follows is the per-entity context — how 861 sits in the broader integer properties and number-guessing puzzles distribution and which underlying factors drive the headline numbers.
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.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for 861’s peers within positive integers within the NumGrid target pool. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.
Frequently asked
Is 861 a prime number?
No. 861 is composite. Its prime factorization is 3 × 7 × 41.
What are the factors of 861?
The factors (divisors) of 861 are 1, 3, 7, 21, 41, 123, 287, 861.
What is 861 in binary?
861 in binary is 1101011101. In hexadecimal it's 35D.
What is 861 as a Roman numeral?
861 in Roman numerals is DCCCLXI.
What's the digit sum of 861?
Adding the digits of 861: 8 + 6 + 1 = 15.