The number 1511
1511 is the 240th prime number. Its only divisors are 1 and 1511.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1511: the 240th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
1511 is prime, so its only factors are 1 and 1511. It is the 240th prime; the next prime is 1523 and the one before is 1499.
- 3
The divisors add up to 1512; without 1511 itself that is 1, so 1511 is deficient (1 is less than 1511). Euler's totient φ(1511) = 1510 numbers up to 1511 share no factor with it.
- 4
The digits of 1511 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 91 steps to reach 1.
1511 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1512 |
| Euler totient φ(n) | 1510 |
| Square | 2283121 |
| Cube | 3449795831 |
| Square root | 38.871583 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 91 |
| Scientific notation | 1.511 × |
1511 in other forms
| Form | Value |
|---|---|
| In words | one thousand five hundred and eleven |
| Roman numerals | MDXI |
| Binary (base 2) | 10111100111 |
| Octal (base 8) | 2747 |
| Hexadecimal (base 16) | 5E7 |
| Base 3 | 2001222 |
| As time | 1511 seconds = 25 min 11 s |
Is 1511 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 3) | 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 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1511 a prime number?
Yes. 1511 is divisible only by 1 and itself.
What are the factors of 1511?
1, 1511.
What is 1511 in binary?
10111100111 (hexadecimal 5E7, octal 2747).
What is the square root of 1511?
About 38.8716.
What is 1511 in Roman numerals?
MDXI.
Is 1511 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 1511?
1511 is the 240th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.