The number 55640
55640 is a composite number with 32 divisors. Its prime factorisation is × 5 × 13 × 107. Divisors (32): 1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 107, 130, 214 … 55640.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55640: a Harshad number: divisible by its digit sum 20.
- 2
55640 is composite. Its prime factorisation is
- 3
The divisors add up to 136080; without 55640 itself that is 80440, so 55640 is abundant (80440 is more than 55640). Euler's totient φ(55640) = 20352 numbers up to 55640 share no factor with it.
- 4
The digits of 55640 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 153 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55640 = 2^{3} \times 5 \times 13 \times 107 \]55640 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 136080 |
| Euler totient φ(n) | 20352 |
| Square | 3095809600 |
| Cube | 172250846144000 |
| Square root | 235.881326 (= 2√13910) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 153 |
| Scientific notation | 5.564 × |
55640 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand six hundred and forty |
| Binary (base 2) | 1101100101011000 |
| Octal (base 8) | 154530 |
| Hexadecimal (base 16) | D958 |
| Base 3 | 2211022202 |
| As time | 55640 seconds = 15 h 27 min 20 s |
Is 55640 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (55640 ÷ 2 = 27820) | 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 (55640 ÷ 4 = 13910) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (55640 ÷ 5 = 11128) | 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 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 | Yes (55640 ÷ 8 = 6955) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (55640 ÷ 10 = 5564) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | 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 55640 a prime number?
No. 55640 = × 5 × 13 × 107, so it is divisible by 2.
What are the factors of 55640?
1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 107, 130, 214, 260, 428, 520, 535, 856, 1070, 1391, 2140, 2782, 4280, 5564, 6955, 11128, 13910, 27820, 55640.
What is 55640 in binary?
1101100101011000 (hexadecimal D958, octal 154530).
What is the square root of 55640?
About 235.8813, exactly 2√13910.
Is 55640 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 55640?
55640 is a Harshad number: divisible by its digit sum 20.