The number 55720
55720 is a composite number with 32 divisors. Its prime factorisation is × 5 × 7 × 199. Divisors (32): 1, 2, 4, 5, 7, 8, 10, 14, 20, 28, 35, 40, 56, 70, 140, 199 … 55720.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55720: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
55720 is composite. Its prime factorisation is
- 3
The divisors add up to 144000; without 55720 itself that is 88280, so 55720 is abundant (88280 is more than 55720). Euler's totient φ(55720) = 19008 numbers up to 55720 share no factor with it.
- 4
The digits of 55720 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 34 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55720 = 2^{3} \times 5 \times 7 \times 199 \]55720 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 144000 |
| Euler totient φ(n) | 19008 |
| Square | 3104718400 |
| Cube | 172994909248000 |
| Square root | 236.050842 (= 2√13930) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 34 |
| Scientific notation | 5.572 × |
55720 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand seven hundred and twenty |
| Binary (base 2) | 1101100110101000 |
| Octal (base 8) | 154650 |
| Hexadecimal (base 16) | D9A8 |
| Base 3 | 2211102201 |
| As time | 55720 seconds = 15 h 28 min 40 s |
Is 55720 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (55720 ÷ 2 = 27860) | 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 (55720 ÷ 4 = 13930) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (55720 ÷ 5 = 11144) | 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 | Yes (55720 ÷ 7 = 7960) | 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 (55720 ÷ 8 = 6965) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (55720 ÷ 10 = 5572) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | 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 55720 a prime number?
No. 55720 = × 5 × 7 × 199, so it is divisible by 2.
What are the factors of 55720?
1, 2, 4, 5, 7, 8, 10, 14, 20, 28, 35, 40, 56, 70, 140, 199, 280, 398, 796, 995, 1393, 1592, 1990, 2786, 3980, 5572, 6965, 7960, 11144, 13930, 27860, 55720.
What is 55720 in binary?
1101100110101000 (hexadecimal D9A8, octal 154650).
What is the square root of 55720?
About 236.0508, exactly 2√13930.
Is 55720 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 55720?
55720 is a happy number: repeatedly adding the squares of its digits reaches 1.