The number 18913
18913 is a twin prime (18911 and 18913 are both prime) and the 2152nd prime number. Its only divisors are 1 and 18913.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18913: a twin prime (18911 and 18913 are both prime); the 2152nd prime number.
- 2
18913 is prime, so its only factors are 1 and 18913. It is the 2152nd prime; the next prime is 18917 and the one before is 18911.
- 3
The divisors add up to 18914; without 18913 itself that is 1, so 18913 is deficient (1 is less than 18913). Euler's totient φ(18913) = 18912 numbers up to 18913 share no factor with it.
- 4
The digits of 18913 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 61 steps to reach 1.
18913 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 18914 |
| Euler totient φ(n) | 18912 |
| Square | 357701569 |
| Cube | 6765209774497 |
| Square root | 137.524543 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 61 |
| Scientific notation | 1.8913 × |
18913 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand nine hundred and thirteen |
| Binary (base 2) | 100100111100001 |
| Octal (base 8) | 44741 |
| Hexadecimal (base 16) | 49E1 |
| Base 3 | 221221111 |
| As time | 18913 seconds = 5 h 15 min 13 s |
Is 18913 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 3) | 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 6) | 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 1) | 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 3) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18913 a prime number?
Yes. 18913 is divisible only by 1 and itself.
What are the factors of 18913?
1, 18913.
What is 18913 in binary?
100100111100001 (hexadecimal 49E1, octal 44741).
What is the square root of 18913?
About 137.5245.
Is 18913 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 18913?
18913 is a twin prime (18911 and 18913 are both prime); the 2152nd prime number.