The number 67921
67921 is a composite number with 8 divisors. Its prime factorisation is 7 × 31 × 313. Divisors (8): 1, 7, 31, 217, 313, 2191, 9703, 67921.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
67921 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
67921 is composite. Its prime factorisation is
- 3
The divisors add up to 80384; without 67921 itself that is 12463, so 67921 is deficient (12463 is less than 67921). Euler's totient φ(67921) = 56160 numbers up to 67921 share no factor with it.
- 4
The digits of 67921 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 67921 = 7 \times 31 \times 313 \]
67921 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 80384 |
| Euler totient φ(n) | 56160 |
| Square | 4613262241 |
| Cube | 313337384670961 |
| Square root | 260.616577 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 99 |
| Scientific notation | 6.7921 × |
67921 in other forms
| Form | Value |
|---|---|
| In words | sixty-seven thousand nine hundred and twenty-one |
| Binary (base 2) | 10000100101010001 |
| Octal (base 8) | 204521 |
| Hexadecimal (base 16) | 10951 |
| Base 3 | 10110011121 |
| As time | 67921 seconds = 18 h 52 min 1 s |
Is 67921 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 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (67921 ÷ 7 = 9703) | 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 7) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 67921 a prime number?
No. 67921 = 7 × 31 × 313, so it is divisible by 7.
What are the factors of 67921?
1, 7, 31, 217, 313, 2191, 9703, 67921.
What is 67921 in binary?
10000100101010001 (hexadecimal 10951, octal 204521).
What is the square root of 67921?
About 260.6166.
Is 67921 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 67921?
It is a composite number with 8 divisors.