√241 at a glance
- Exact value
- √241
- Decimal (10 places)
- 15.5241746963
- Rounded
- 15.5 · 15.52 · 15.524
- Perfect square?
- No — between 15² and 16²
- Rational?
- Irrational
- Both square roots
- ±15.524175
- Prime factorization
- 241
- Cube root
- 6.223084
How to simplify √241
241 is a prime number, so its only factors are 1 and 241. There is no perfect-square factor to pull out, which means √241 is already in its simplest radical form.
The square root of any prime is irrational. If √241 were a fraction a/b in lowest terms, then a² = 241b², so 241 would divide a — and then 241 would divide b too, contradicting “lowest terms.” That is why the decimal 15.5241746963 is only a rounded value.
Where √241 sits between perfect squares
225 = 15² and 256 = 16² are the nearest perfect squares, so √241 lies between 15 and 16. 241 is 16 above 225 and 15 below 256, so the root is closer to 16.
- Straight line between 225 and 256: 15.5161 (0.05% low)
- Tangent from 15, i.e. 15 + 16 ÷ 30: 15.5333 (0.06% high)
- Tangent from 16, i.e. 16 − 15 ÷ 32: 15.5313 (0.05% high)
For √241 the tangent at 16 wins, missing by only 0.0071. Tangent estimates shine when the number sits close to a perfect square — here 241 is just 15 below 256.
Finding √241 with the Babylonian method
This is Newton’s method applied to f(x) = x² − 241: following the tangent line down to zero simplifies to averaging x with 241 ÷ x.
Start from the nearest whole number, 16 (16² = 256):
| Step | Guess x | 241 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 16.0000000000 | 15.0625000000 | 15.5312500000 | 2 |
| 2 | 15.5312500000 | 15.5171026157 | 15.5241763078 | 5 |
| 3 | 15.5241763078 | 15.5241730847 | 15.5241746963 | all 10 shown |
The count of correct decimals went 2, 5 and all 10 over 3 steps — roughly doubling each time — until the guess matched √241 = 15.5241746963 to every decimal shown.
√241 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √241 the pattern is [15; 1, 1, 9, 1, 5, 3, 3, 1, 1, 3, 3, 5, …] with the block of 17 terms after the semicolon repeating forever (only the first 12 of the 17 are shown). A pattern that never ends is one more proof that √241 is irrational.
Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:
| Fraction | Decimal | Error |
|---|---|---|
| 15/1 | 15.0000000000 | 5.2 × 10⁻¹ |
| 16/1 | 16.0000000000 | 4.8 × 10⁻¹ |
| 31/2 | 15.5000000000 | 2.4 × 10⁻² |
| 295/19 | 15.5263157895 | 2.1 × 10⁻³ |
| 326/21 | 15.5238095238 | 3.7 × 10⁻⁴ |
| 1,925/124 | 15.5241935484 | 1.9 × 10⁻⁵ |
The same fractions solve Pell’s equation, x² − 241y² = 1. Its smallest solution in positive whole numbers is x = 10,085,143,557,001,249, y = 649,641,205,044,600 — 17 digits for x, even though 241 is small, which is what makes Pell’s equation famous. Because the period is odd, the equation with −1 on the right also has a solution: 71,011,068² − 241 × 4,574,225² = −1.
√241 in geometry and everyday measurements
- A square patio or deck of 241 square feet is about 15.52 ft (15 ft 6 in) on each side, so edging all the way around takes 4 × √241 ≈ 62.1 ft.
- 241 = 4² + 15², so by the Pythagorean theorem √241 is the diagonal of a 4 × 15 rectangle — and the distance between the points (0, 0) and (4, 15) on a grid.
Square roots near √241 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √238 | √238 | 15.4272 | No |
| √239 | √239 | 15.4596 | No |
| √240 | 4√15 | 15.4919 | No |
| √241 | √241 | 15.5242 | No |
| √242 | 11√2 | 15.5563 | No |
| √243 | 9√3 | 15.5885 | No |
| √244 | 2√61 | 15.6205 | No |
- The cube root of 241 is about 6.223084.
- Four times the radicand doubles the root: √964 = 2 × √241 ≈ 31.048349.
Frequently asked questions
What is the square root of 241?
The square root of 241 is √241, about 15.5241746963. The negative root, −15.524175, also squares to 241.
Is the square root of 241 rational or irrational?
Irrational. 241 is not a perfect square — it falls between 225 and 256 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √241 be simplified?
No. 241 is prime, so there is no perfect square to take out of the radical.
What is √241 rounded to two decimal places?
√241 ≈ 15.52 to two decimal places (15.5 to one, 15.524 to three). Check: 15.52² = 240.8704, close to 241.