The number 531
531 is a composite number with 6 divisors. Its prime factorisation is × 59. Divisors (6): 1, 3, 9, 59, 177, 531.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 531: a Harshad number: divisible by its digit sum 9.
- 2
531 is composite. Its prime factorisation is
- 3
The divisors add up to 780; without 531 itself that is 249, so 531 is deficient (249 is less than 531). Euler's totient φ(531) = 348 numbers up to 531 share no factor with it.
- 4
The digits of 531 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 123 steps to reach 1.
LaTeX source of the formulas on this page
\[ 531 = 3^{2} \times 59 \]531 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 780 |
| Euler totient φ(n) | 348 |
| Square | 281961 |
| Cube | 149721291 |
| Square root | 23.043437 (= 3√59) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 123 |
| Scientific notation | 5.31 × |
531 in other forms
| Form | Value |
|---|---|
| In words | five hundred and thirty-one |
| Roman numerals | DXXXI |
| Binary (base 2) | 1000010011 |
| Octal (base 8) | 1023 |
| Hexadecimal (base 16) | 213 |
| Base 3 | 201200 |
| As time | 531 seconds = 8 min 51 s |
Is 531 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (531 ÷ 3 = 177) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (531 ÷ 9 = 59) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 531 a prime number?
No. 531 = × 59, so it is divisible by 3.
What are the factors of 531?
1, 3, 9, 59, 177, 531.
What is 531 in binary?
1000010011 (hexadecimal 213, octal 1023).
What is the square root of 531?
About 23.0434, exactly 3√59.
What is 531 in Roman numerals?
DXXXI.
Is 531 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 531?
531 is a Harshad number: divisible by its digit sum 9.