The number 8521
8521 is the 1062nd prime number. Its only divisors are 1 and 8521.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 8521: the 1062nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
8521 is prime, so its only factors are 1 and 8521. It is the 1062nd prime; the next prime is 8527 and the one before is 8513.
- 3
The divisors add up to 8522; without 8521 itself that is 1, so 8521 is deficient (1 is less than 8521). Euler's totient φ(8521) = 8520 numbers up to 8521 share no factor with it.
- 4
The digits of 8521 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 78 steps to reach 1.
8521 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 8522 |
| Euler totient φ(n) | 8520 |
| Square | 72607441 |
| Cube | 618688004761 |
| Square root | 92.309263 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 78 |
| Scientific notation | 8.521 × |
8521 in other forms
| Form | Value |
|---|---|
| In words | eight thousand five hundred and twenty-one |
| Binary (base 2) | 10000101001001 |
| Octal (base 8) | 20511 |
| Hexadecimal (base 16) | 2149 |
| Base 3 | 102200121 |
| As time | 8521 seconds = 2 h 22 min 1 s |
Is 8521 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 2) | 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 7) | 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 8521 a prime number?
Yes. 8521 is divisible only by 1 and itself.
What are the factors of 8521?
1, 8521.
What is 8521 in binary?
10000101001001 (hexadecimal 2149, octal 20511).
What is the square root of 8521?
About 92.3093.
Is 8521 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 8521?
8521 is the 1062nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.