The number 19121
19121 is the 2170th prime number. Its only divisors are 1 and 19121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 19121: the 2170th prime number.
- 2
19121 is prime, so its only factors are 1 and 19121. It is the 2170th prime; the next prime is 19139 and the one before is 19087.
- 3
The divisors add up to 19122; without 19121 itself that is 1, so 19121 is deficient (1 is less than 19121). Euler's totient φ(19121) = 19120 numbers up to 19121 share no factor with it.
- 4
The digits of 19121 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 79 steps to reach 1.
19121 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 19122 |
| Euler totient φ(n) | 19120 |
| Square | 365612641 |
| Cube | 6990879308561 |
| Square root | 138.278704 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 79 |
| Scientific notation | 1.9121 × |
19121 in other forms
| Form | Value |
|---|---|
| In words | nineteen thousand one hundred and twenty-one |
| Binary (base 2) | 100101010110001 |
| Octal (base 8) | 45261 |
| Hexadecimal (base 16) | 4AB1 |
| Base 3 | 222020012 |
| As time | 19121 seconds = 5 h 18 min 41 s |
Is 19121 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 2) | 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 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 19121 a prime number?
Yes. 19121 is divisible only by 1 and itself.
What are the factors of 19121?
1, 19121.
What is 19121 in binary?
100101010110001 (hexadecimal 4AB1, octal 45261).
What is the square root of 19121?
About 138.2787.
Is 19121 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 19121?
19121 is the 2170th prime number.