The number 55405
55405 is a composite number with 8 divisors. Its prime factorisation is 5 × 7 × 1583. Divisors (8): 1, 5, 7, 35, 1583, 7915, 11081, 55405.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55405: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
55405 is composite. Its prime factorisation is
- 3
The divisors add up to 76032; without 55405 itself that is 20627, so 55405 is deficient (20627 is less than 55405). Euler's totient φ(55405) = 37968 numbers up to 55405 share no factor with it.
- 4
The digits of 55405 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 78 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55405 = 5 \times 7 \times 1583 \]
55405 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 76032 |
| Euler totient φ(n) | 37968 |
| Square | 3069714025 |
| Cube | 170077505555125 |
| Square root | 235.382667 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 78 |
| Scientific notation | 5.5405 × |
55405 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand four hundred and five |
| Binary (base 2) | 1101100001101101 |
| Octal (base 8) | 154155 |
| Hexadecimal (base 16) | D86D |
| Base 3 | 2211000001 |
| As time | 55405 seconds = 15 h 23 min 25 s |
Is 55405 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (55405 ÷ 5 = 11081) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (55405 ÷ 7 = 7915) | 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 5) | 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 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 55405 a prime number?
No. 55405 = 5 × 7 × 1583, so it is divisible by 5.
What are the factors of 55405?
1, 5, 7, 35, 1583, 7915, 11081, 55405.
What is 55405 in binary?
1101100001101101 (hexadecimal D86D, octal 154155).
What is the square root of 55405?
About 235.3827.
Is 55405 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 55405?
55405 is a happy number: repeatedly adding the squares of its digits reaches 1.