even, composite, perfect square · 400th positive integer
The number 400
400 is an even composite number. It is the 400th positive integer.
Quick reference
| Prime factorization | 2 × 2 × 2 × 2 × 5 × 5 |
| Divisors | 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400 |
| Binary | 110010000 |
| Hexadecimal | 0x190 |
| Roman numeral | CD |
| Digit sum | 4 |
| Properties | even, composite, perfect square |
Reading 400 in NumGrid context
400 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.
Every number on this page links back to classical number theory plus NumGrid solver-derived puzzle statistics; the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for 400’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 400 a prime number?
No. 400 is composite. Its prime factorization is 2 × 2 × 2 × 2 × 5 × 5.
What are the factors of 400?
The factors (divisors) of 400 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400.
What is 400 in binary?
400 in binary is 110010000. In hexadecimal it's 190.
What is 400 as a Roman numeral?
400 in Roman numerals is CD.
What's the digit sum of 400?
Adding the digits of 400: 4 + 0 + 0 = 4.