The number 30987
30987 is a composite number with 12 divisors. Its prime factorisation is × 11 × 313. Divisors (12): 1, 3, 9, 11, 33, 99, 313, 939, 2817, 3443, 10329, 30987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 30987: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
30987 is composite. Its prime factorisation is
- 3
The divisors add up to 48984; without 30987 itself that is 17997, so 30987 is deficient (17997 is less than 30987). Euler's totient φ(30987) = 18720 numbers up to 30987 share no factor with it.
- 4
The digits of 30987 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 30987 = 3^{2} \times 11 \times 313 \]30987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 48984 |
| Euler totient φ(n) | 18720 |
| Square | 960194169 |
| Cube | 29753536714803 |
| Square root | 176.031247 (= 3√3443) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.0987 × |
30987 in other forms
| Form | Value |
|---|---|
| In words | thirty thousand nine hundred and eighty-seven |
| Binary (base 2) | 111100100001011 |
| Octal (base 8) | 74413 |
| Hexadecimal (base 16) | 790B |
| Base 3 | 1120111200 |
| As time | 30987 seconds = 8 h 36 min 27 s |
Is 30987 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 (30987 ÷ 3 = 10329) | 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 2) | 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 5) | 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 (30987 ÷ 9 = 3443) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (30987 ÷ 11 = 2817) | 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 30987 a prime number?
No. 30987 = × 11 × 313, so it is divisible by 3.
What are the factors of 30987?
1, 3, 9, 11, 33, 99, 313, 939, 2817, 3443, 10329, 30987.
What is 30987 in binary?
111100100001011 (hexadecimal 790B, octal 74413).
What is the square root of 30987?
About 176.0312, exactly 3√3443.
Is 30987 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 30987?
30987 is a happy number: repeatedly adding the squares of its digits reaches 1.