The number 61218
61218 is a composite number with 24 divisors. Its prime factorisation is 2 × × 19 × 179. Divisors (24): 1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 179, 342, 358, 537, 1074 … 61218.
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How to work it out
- 1
What is special about 61218: a Harshad number: divisible by its digit sum 18.
- 2
61218 is composite. Its prime factorisation is
- 3
The divisors add up to 140400; without 61218 itself that is 79182, so 61218 is abundant (79182 is more than 61218). Euler's totient φ(61218) = 19224 numbers up to 61218 share no factor with it.
- 4
The digits of 61218 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 179 steps to reach 1.
LaTeX source of the formulas on this page
\[ 61218 = 2 \times 3^{2} \times 19 \times 179 \]61218 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 140400 |
| Euler totient φ(n) | 19224 |
| Square | 3747643524 |
| Cube | 229423241252232 |
| Square root | 247.422715 (= 3√6802) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 179 |
| Scientific notation | 6.1218 × |
61218 in other forms
| Form | Value |
|---|---|
| In words | sixty-one thousand two hundred and eighteen |
| Binary (base 2) | 1110111100100010 |
| Octal (base 8) | 167442 |
| Hexadecimal (base 16) | EF22 |
| Base 3 | 10002222100 |
| As time | 61218 seconds = 17 h 0 min 18 s |
Is 61218 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (61218 ÷ 2 = 30609) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (61218 ÷ 3 = 20406) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (61218 ÷ 6 = 10203) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (61218 ÷ 9 = 6802) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 61218 a prime number?
No. 61218 = 2 × × 19 × 179, so it is divisible by 2.
What are the factors of 61218?
1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 179, 342, 358, 537, 1074, 1611, 3222, 3401, 6802, 10203, 20406, 30609, 61218.
What is 61218 in binary?
1110111100100010 (hexadecimal EF22, octal 167442).
What is the square root of 61218?
About 247.4227, exactly 3√6802.
Is 61218 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 61218?
61218 is a Harshad number: divisible by its digit sum 18.