The number 67521
67521 is a binary palindrome (10000011111000001). Its prime factorisation is 3 × 71 × 317. Divisors (8): 1, 3, 71, 213, 317, 951, 22507, 67521.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 67521: a binary palindrome (10000011111000001).
- 2
67521 is composite. Its prime factorisation is
- 3
The divisors add up to 91584; without 67521 itself that is 24063, so 67521 is deficient (24063 is less than 67521). Euler's totient φ(67521) = 44240 numbers up to 67521 share no factor with it.
- 4
The digits of 67521 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 161 steps to reach 1.
LaTeX source of the formulas on this page
\[ 67521 = 3 \times 71 \times 317 \]
67521 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 91584 |
| Euler totient φ(n) | 44240 |
| Square | 4559085441 |
| Cube | 307834008061761 |
| Square root | 259.848033 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 161 |
| Scientific notation | 6.7521 × |
67521 in other forms
| Form | Value |
|---|---|
| In words | sixty-seven thousand five hundred and twenty-one |
| Binary (base 2) | 10000011111000001 |
| Octal (base 8) | 203701 |
| Hexadecimal (base 16) | 107C1 |
| Base 3 | 10102121210 |
| As time | 67521 seconds = 18 h 45 min 21 s |
Is 67521 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 (67521 ÷ 3 = 22507) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | 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 1) | 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 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 67521 a prime number?
No. 67521 = 3 × 71 × 317, so it is divisible by 3.
What are the factors of 67521?
1, 3, 71, 213, 317, 951, 22507, 67521.
What is 67521 in binary?
10000011111000001 (hexadecimal 107C1, octal 203701).
What is the square root of 67521?
About 259.8480.
Is 67521 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 67521?
67521 is a binary palindrome (10000011111000001).