The number 2521
2521 is the 369th prime number. Its only divisors are 1 and 2521.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2521: the 369th prime number.
- 2
2521 is prime, so its only factors are 1 and 2521. It is the 369th prime; the next prime is 2531 and the one before is 2503.
- 3
The divisors add up to 2522; without 2521 itself that is 1, so 2521 is deficient (1 is less than 2521). Euler's totient φ(2521) = 2520 numbers up to 2521 share no factor with it.
- 4
The digits of 2521 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
2521 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 2522 |
| Euler totient φ(n) | 2520 |
| Square | 6355441 |
| Cube | 16022066761 |
| Square root | 50.209561 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 40 |
| Scientific notation | 2.521 × |
2521 in other forms
| Form | Value |
|---|---|
| In words | two thousand five hundred and twenty-one |
| Roman numerals | MMDXXI |
| Binary (base 2) | 100111011001 |
| Octal (base 8) | 4731 |
| Hexadecimal (base 16) | 9D9 |
| Base 3 | 10110101 |
| As time | 2521 seconds = 42 min 1 s |
Is 2521 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 1) | 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 1) | 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 2) | 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 2521 a prime number?
Yes. 2521 is divisible only by 1 and itself.
What are the factors of 2521?
1, 2521.
What is 2521 in binary?
100111011001 (hexadecimal 9D9, octal 4731).
What is the square root of 2521?
About 50.2096.
What is 2521 in Roman numerals?
MMDXXI.
Is 2521 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 2521?
2521 is the 369th prime number.