The number 55381
55381 is the 5625th prime number. Its only divisors are 1 and 55381.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55381: the 5625th prime number.
- 2
55381 is prime, so its only factors are 1 and 55381. It is the 5625th prime; the next prime is 55399 and the one before is 55373.
- 3
The divisors add up to 55382; without 55381 itself that is 1, so 55381 is deficient (1 is less than 55381). Euler's totient φ(55381) = 55380 numbers up to 55381 share no factor with it.
- 4
The digits of 55381 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.
55381 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 55382 |
| Euler totient φ(n) | 55380 |
| Square | 3067055161 |
| Cube | 169856581871341 |
| Square root | 235.331681 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 153 |
| Scientific notation | 5.5381 × |
55381 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand three hundred and eighty-one |
| Binary (base 2) | 1101100001010101 |
| Octal (base 8) | 154125 |
| Hexadecimal (base 16) | D855 |
| Base 3 | 2210222011 |
| As time | 55381 seconds = 15 h 23 min 1 s |
Is 55381 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 | No (remainder 1) | 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 | 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 | No (remainder 5) | 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 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 55381 a prime number?
Yes. 55381 is divisible only by 1 and itself.
What are the factors of 55381?
1, 55381.
What is 55381 in binary?
1101100001010101 (hexadecimal D855, octal 154125).
What is the square root of 55381?
About 235.3317.
Is 55381 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 55381?
55381 is the 5625th prime number.