The number 90121
90121 is the 8728th prime number. Its only divisors are 1 and 90121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 90121: the 8728th prime number.
- 2
90121 is prime, so its only factors are 1 and 90121. It is the 8728th prime; the next prime is 90127 and the one before is 90107.
- 3
The divisors add up to 90122; without 90121 itself that is 1, so 90121 is deficient (1 is less than 90121). Euler's totient φ(90121) = 90120 numbers up to 90121 share no factor with it.
- 4
The digits of 90121 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 133 steps to reach 1.
90121 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 90122 |
| Euler totient φ(n) | 90120 |
| Square | 8121794641 |
| Cube | 731944254841561 |
| Square root | 300.201599 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 133 |
| Scientific notation | 9.0121 × |
90121 in other forms
| Form | Value |
|---|---|
| In words | ninety thousand one hundred and twenty-one |
| Binary (base 2) | 10110000000001001 |
| Octal (base 8) | 260011 |
| Hexadecimal (base 16) | 16009 |
| Base 3 | 11120121211 |
| As time | 90121 seconds = 25 h 2 min 1 s |
Is 90121 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 3) | 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 1) | 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 90121 a prime number?
Yes. 90121 is divisible only by 1 and itself.
What are the factors of 90121?
1, 90121.
What is 90121 in binary?
10110000000001001 (hexadecimal 16009, octal 260011).
What is the square root of 90121?
About 300.2016.
Is 90121 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 90121?
90121 is the 8728th prime number.