The number 61820
61820 is a composite number with 24 divisors. Its prime factorisation is × 5 × 11 × 281. Divisors (24): 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220, 281, 562, 1124, 1405 … 61820.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
61820 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
61820 is composite. Its prime factorisation is
- 3
The divisors add up to 142128; without 61820 itself that is 80308, so 61820 is abundant (80308 is more than 61820). Euler's totient φ(61820) = 22400 numbers up to 61820 share no factor with it.
- 4
The digits of 61820 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 91 steps to reach 1.
LaTeX source of the formulas on this page
\[ 61820 = 2^{2} \times 5 \times 11 \times 281 \]61820 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 142128 |
| Euler totient φ(n) | 22400 |
| Square | 3821712400 |
| Cube | 236258260568000 |
| Square root | 248.636281 (= 2√15455) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 91 |
| Scientific notation | 6.182 × |
61820 in other forms
| Form | Value |
|---|---|
| In words | sixty-one thousand eight hundred and twenty |
| Binary (base 2) | 1111000101111100 |
| Octal (base 8) | 170574 |
| Hexadecimal (base 16) | F17C |
| Base 3 | 10010210122 |
| As time | 61820 seconds = 17 h 10 min 20 s |
Is 61820 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (61820 ÷ 2 = 30910) | 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 (61820 ÷ 4 = 15455) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (61820 ÷ 5 = 12364) | 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 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (61820 ÷ 10 = 6182) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (61820 ÷ 11 = 5620) | 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 61820 a prime number?
No. 61820 = × 5 × 11 × 281, so it is divisible by 2.
What are the factors of 61820?
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220, 281, 562, 1124, 1405, 2810, 3091, 5620, 6182, 12364, 15455, 30910, 61820.
What is 61820 in binary?
1111000101111100 (hexadecimal F17C, octal 170574).
What is the square root of 61820?
About 248.6363, exactly 2√15455.
Is 61820 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 61820?
It is a composite number with 24 divisors.