The number 68121
68121 is a perfect square (261²). Its prime factorisation is × . Divisors (15): 1, 3, 9, 27, 29, 81, 87, 261, 783, 841, 2349, 2523, 7569, 22707, 68121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 68121: a perfect square (261²).
- 2
68121 is composite. Its prime factorisation is
- 3
The divisors add up to 105391; without 68121 itself that is 37270, so 68121 is deficient (37270 is less than 68121). Euler's totient φ(68121) = 43848 numbers up to 68121 share no factor with it.
- 4
The digits of 68121 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 161 steps to reach 1.
LaTeX source of the formulas on this page
\[ 68121 = 3^{4} \times 29^{2} \]68121 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 15 |
| Sum of divisors | 105391 |
| Euler totient φ(n) | 43848 |
| Square | 4640470641 |
| Cube | 316113500535561 |
| Square root | 261 |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 161 |
| Scientific notation | 6.8121 × |
| Perfect power |
68121 in other forms
| Form | Value |
|---|---|
| In words | sixty-eight thousand one hundred and twenty-one |
| Binary (base 2) | 10000101000011001 |
| Octal (base 8) | 205031 |
| Hexadecimal (base 16) | 10A19 |
| Base 3 | 10110110000 |
| As time | 68121 seconds = 18 h 55 min 21 s |
Is 68121 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 (68121 ÷ 3 = 22707) | 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 4) | 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 | Yes (68121 ÷ 9 = 7569) | 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 9) | 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 68121 a prime number?
No. 68121 = × , so it is divisible by 3.
What are the factors of 68121?
1, 3, 9, 27, 29, 81, 87, 261, 783, 841, 2349, 2523, 7569, 22707, 68121.
What is 68121 in binary?
10000101000011001 (hexadecimal 10A19, octal 205031).
What is the square root of 68121?
261, because 261 × 261 = 68121.
Is 68121 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 68121?
68121 is a perfect square (261²).