The number 39820
39820 is a composite number with 24 divisors. Its prime factorisation is × 5 × 11 × 181. Divisors (24): 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 181, 220, 362, 724, 905 … 39820.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 39820: a Harshad number: divisible by its digit sum 22.
- 2
39820 is composite. Its prime factorisation is
- 3
The divisors add up to 91728; without 39820 itself that is 51908, so 39820 is abundant (51908 is more than 39820). Euler's totient φ(39820) = 14400 numbers up to 39820 share no factor with it.
- 4
The digits of 39820 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 93 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39820 = 2^{2} \times 5 \times 11 \times 181 \]39820 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 91728 |
| Euler totient φ(n) | 14400 |
| Square | 1585632400 |
| Cube | 63139882168000 |
| Square root | 199.549493 (= 2√9955) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 93 |
| Scientific notation | 3.982 × |
39820 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand eight hundred and twenty |
| Binary (base 2) | 1001101110001100 |
| Octal (base 8) | 115614 |
| Hexadecimal (base 16) | 9B8C |
| Base 3 | 2000121211 |
| As time | 39820 seconds = 11 h 3 min 40 s |
Is 39820 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39820 ÷ 2 = 19910) | 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 | Yes (39820 ÷ 4 = 9955) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (39820 ÷ 5 = 7964) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (39820 ÷ 10 = 3982) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (39820 ÷ 11 = 3620) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39820 a prime number?
No. 39820 = × 5 × 11 × 181, so it is divisible by 2.
What are the factors of 39820?
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 181, 220, 362, 724, 905, 1810, 1991, 3620, 3982, 7964, 9955, 19910, 39820.
What is 39820 in binary?
1001101110001100 (hexadecimal 9B8C, octal 115614).
What is the square root of 39820?
About 199.5495, exactly 2√9955.
Is 39820 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 39820?
39820 is a Harshad number: divisible by its digit sum 22.