The number 17720
17720 is a composite number with 16 divisors. Its prime factorisation is × 5 × 443. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 443, 886, 1772, 2215, 3544, 4430, 8860, 17720.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 17720: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
17720 is composite. Its prime factorisation is
- 3
The divisors add up to 39960; without 17720 itself that is 22240, so 17720 is abundant (22240 is more than 17720). Euler's totient φ(17720) = 7072 numbers up to 17720 share no factor with it.
- 4
The digits of 17720 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 123 steps to reach 1.
LaTeX source of the formulas on this page
\[ 17720 = 2^{3} \times 5 \times 443 \]17720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 39960 |
| Euler totient φ(n) | 7072 |
| Square | 313998400 |
| Cube | 5564051648000 |
| Square root | 133.116490 (= 2√4430) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 123 |
| Scientific notation | 1.772 × |
17720 in other forms
| Form | Value |
|---|---|
| In words | seventeen thousand seven hundred and twenty |
| Binary (base 2) | 100010100111000 |
| Octal (base 8) | 42470 |
| Hexadecimal (base 16) | 4538 |
| Base 3 | 220022022 |
| As time | 17720 seconds = 4 h 55 min 20 s |
Is 17720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (17720 ÷ 2 = 8860) | 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 (17720 ÷ 4 = 4430) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (17720 ÷ 5 = 3544) | 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 | Yes (17720 ÷ 8 = 2215) | 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 (17720 ÷ 10 = 1772) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 17720 a prime number?
No. 17720 = × 5 × 443, so it is divisible by 2.
What are the factors of 17720?
1, 2, 4, 5, 8, 10, 20, 40, 443, 886, 1772, 2215, 3544, 4430, 8860, 17720.
What is 17720 in binary?
100010100111000 (hexadecimal 4538, octal 42470).
What is the square root of 17720?
About 133.1165, exactly 2√4430.
Is 17720 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 17720?
17720 is a happy number: repeatedly adding the squares of its digits reaches 1.