The number 6987
6987 is a composite number with 8 divisors. Its prime factorisation is 3 × 17 × 137. Divisors (8): 1, 3, 17, 51, 137, 411, 2329, 6987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 6987: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
6987 is composite. Its prime factorisation is
- 3
The divisors add up to 9936; without 6987 itself that is 2949, so 6987 is deficient (2949 is less than 6987). Euler's totient φ(6987) = 4352 numbers up to 6987 share no factor with it.
- 4
The digits of 6987 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 150 steps to reach 1.
LaTeX source of the formulas on this page
\[ 6987 = 3 \times 17 \times 137 \]
6987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 9936 |
| Euler totient φ(n) | 4352 |
| Square | 48818169 |
| Cube | 341092546803 |
| Square root | 83.588277 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 150 |
| Scientific notation | 6.987 × |
6987 in other forms
| Form | Value |
|---|---|
| In words | six thousand nine hundred and eighty-seven |
| Binary (base 2) | 1101101001011 |
| Octal (base 8) | 15513 |
| Hexadecimal (base 16) | 1B4B |
| Base 3 | 100120210 |
| As time | 6987 seconds = 1 h 56 min 27 s |
Is 6987 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 (6987 ÷ 3 = 2329) | 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 1) | 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 | No (remainder 3) | 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 | No (remainder 2) | 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 6987 a prime number?
No. 6987 = 3 × 17 × 137, so it is divisible by 3.
What are the factors of 6987?
1, 3, 17, 51, 137, 411, 2329, 6987.
What is 6987 in binary?
1101101001011 (hexadecimal 1B4B, octal 15513).
What is the square root of 6987?
About 83.5883.
Is 6987 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 6987?
6987 is a happy number: repeatedly adding the squares of its digits reaches 1.