The number 55420
55420 is a composite number with 24 divisors. Its prime factorisation is × 5 × 17 × 163. Divisors (24): 1, 2, 4, 5, 10, 17, 20, 34, 68, 85, 163, 170, 326, 340, 652, 815 … 55420.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55420: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
55420 is composite. Its prime factorisation is
- 3
The divisors add up to 123984; without 55420 itself that is 68564, so 55420 is abundant (68564 is more than 55420). Euler's totient φ(55420) = 20736 numbers up to 55420 share no factor with it.
- 4
The digits of 55420 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 91 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55420 = 2^{2} \times 5 \times 17 \times 163 \]55420 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 123984 |
| Euler totient φ(n) | 20736 |
| Square | 3071376400 |
| Cube | 170215680088000 |
| Square root | 235.414528 (= 2√13855) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 91 |
| Scientific notation | 5.542 × |
55420 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand four hundred and twenty |
| Binary (base 2) | 1101100001111100 |
| Octal (base 8) | 154174 |
| Hexadecimal (base 16) | D87C |
| Base 3 | 2211000121 |
| As time | 55420 seconds = 15 h 23 min 40 s |
Is 55420 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (55420 ÷ 2 = 27710) | 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 (55420 ÷ 4 = 13855) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (55420 ÷ 5 = 11084) | 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 | No (remainder 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (55420 ÷ 10 = 5542) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 55420 a prime number?
No. 55420 = × 5 × 17 × 163, so it is divisible by 2.
What are the factors of 55420?
1, 2, 4, 5, 10, 17, 20, 34, 68, 85, 163, 170, 326, 340, 652, 815, 1630, 2771, 3260, 5542, 11084, 13855, 27710, 55420.
What is 55420 in binary?
1101100001111100 (hexadecimal D87C, octal 154174).
What is the square root of 55420?
About 235.4145, exactly 2√13855.
Is 55420 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 55420?
55420 is a happy number: repeatedly adding the squares of its digits reaches 1.