The number 55840
55840 is a composite number with 24 divisors. Its prime factorisation is × 5 × 349. Divisors (24): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 160, 349, 698, 1396, 1745 … 55840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55840: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
55840 is composite. Its prime factorisation is
- 3
The divisors add up to 132300; without 55840 itself that is 76460, so 55840 is abundant (76460 is more than 55840). Euler's totient φ(55840) = 22272 numbers up to 55840 share no factor with it.
- 4
The digits of 55840 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 153 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55840 = 2^{5} \times 5 \times 349 \]55840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 132300 |
| Euler totient φ(n) | 22272 |
| Square | 3118105600 |
| Cube | 174115016704000 |
| Square root | 236.304888 (= 4√3490) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 153 |
| Scientific notation | 5.584 × |
55840 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand eight hundred and forty |
| Binary (base 2) | 1101101000100000 |
| Octal (base 8) | 155040 |
| Hexadecimal (base 16) | DA20 |
| Base 3 | 2211121011 |
| As time | 55840 seconds = 15 h 30 min 40 s |
Is 55840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (55840 ÷ 2 = 27920) | 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 (55840 ÷ 4 = 13960) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (55840 ÷ 5 = 11168) | 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 1) | 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 (55840 ÷ 8 = 6980) | 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 (55840 ÷ 10 = 5584) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 55840 a prime number?
No. 55840 = × 5 × 349, so it is divisible by 2.
What are the factors of 55840?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 160, 349, 698, 1396, 1745, 2792, 3490, 5584, 6980, 11168, 13960, 27920, 55840.
What is 55840 in binary?
1101101000100000 (hexadecimal DA20, octal 155040).
What is the square root of 55840?
About 236.3049, exactly 4√3490.
Is 55840 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 55840?
55840 is a happy number: repeatedly adding the squares of its digits reaches 1.