The number 68420
68420 is a composite number with 24 divisors. Its prime factorisation is × 5 × 11 × 311. Divisors (24): 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220, 311, 622, 1244, 1555 … 68420.
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How to work it out
- 1
What is special about 68420: a Harshad number: divisible by its digit sum 20.
- 2
68420 is composite. Its prime factorisation is
- 3
The divisors add up to 157248; without 68420 itself that is 88828, so 68420 is abundant (88828 is more than 68420). Euler's totient φ(68420) = 24800 numbers up to 68420 share no factor with it.
- 4
The digits of 68420 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 55 steps to reach 1.
LaTeX source of the formulas on this page
\[ 68420 = 2^{2} \times 5 \times 11 \times 311 \]68420 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 157248 |
| Euler totient φ(n) | 24800 |
| Square | 4681296400 |
| Cube | 320294299688000 |
| Square root | 261.572170 (= 2√17105) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 55 |
| Scientific notation | 6.842 × |
68420 in other forms
| Form | Value |
|---|---|
| In words | sixty-eight thousand four hundred and twenty |
| Binary (base 2) | 10000101101000100 |
| Octal (base 8) | 205504 |
| Hexadecimal (base 16) | 10B44 |
| Base 3 | 10110212002 |
| As time | 68420 seconds = 19 h 0 min 20 s |
Is 68420 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (68420 ÷ 2 = 34210) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (68420 ÷ 4 = 17105) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (68420 ÷ 5 = 13684) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (68420 ÷ 10 = 6842) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (68420 ÷ 11 = 6220) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 68420 a prime number?
No. 68420 = × 5 × 11 × 311, so it is divisible by 2.
What are the factors of 68420?
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220, 311, 622, 1244, 1555, 3110, 3421, 6220, 6842, 13684, 17105, 34210, 68420.
What is 68420 in binary?
10000101101000100 (hexadecimal 10B44, octal 205504).
What is the square root of 68420?
About 261.5722, exactly 2√17105.
Is 68420 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 68420?
68420 is a Harshad number: divisible by its digit sum 20.