odd, composite, palindrome · 161st positive integer
The number 161
161 is an odd composite number. It is the 161st positive integer.
Quick reference
| Prime factorization | 7 × 23 |
| Divisors | 1, 7, 23, 161 |
| Binary | 10100001 |
| Hexadecimal | 0xA1 |
| Roman numeral | CLXI |
| Digit sum | 8 |
| Properties | odd, composite, palindrome |
Reading 161 in NumGrid context
161 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.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for 161’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 161 a prime number?
No. 161 is composite. Its prime factorization is 7 × 23.
What are the factors of 161?
The factors (divisors) of 161 are 1, 7, 23, 161.
What is 161 in binary?
161 in binary is 10100001. In hexadecimal it's A1.
What is 161 as a Roman numeral?
161 in Roman numerals is CLXI.
What's the digit sum of 161?
Adding the digits of 161: 1 + 6 + 1 = 8.