The number 2131
2131 is a twin prime (2129 and 2131 are both prime) and the 321st prime number. Its only divisors are 1 and 2131.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2131: a twin prime (2129 and 2131 are both prime); the 321st prime number.
- 2
2131 is prime, so its only factors are 1 and 2131. It is the 321st prime; the next prime is 2137 and the one before is 2129.
- 3
The divisors add up to 2132; without 2131 itself that is 1, so 2131 is deficient (1 is less than 2131). Euler's totient φ(2131) = 2130 numbers up to 2131 share no factor with it.
- 4
The digits of 2131 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
2131 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 2132 |
| Euler totient φ(n) | 2130 |
| Square | 4541161 |
| Cube | 9677214091 |
| Square root | 46.162756 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 76 |
| Scientific notation | 2.131 × |
2131 in other forms
| Form | Value |
|---|---|
| In words | two thousand one hundred and thirty-one |
| Roman numerals | MMCXXXI |
| Binary (base 2) | 100001010011 |
| Octal (base 8) | 4123 |
| Hexadecimal (base 16) | 853 |
| Base 3 | 2220221 |
| As time | 2131 seconds = 35 min 31 s |
Is 2131 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 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 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 3) | 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 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 2131 a prime number?
Yes. 2131 is divisible only by 1 and itself.
What are the factors of 2131?
1, 2131.
What is 2131 in binary?
100001010011 (hexadecimal 853, octal 4123).
What is the square root of 2131?
About 46.1628.
What is 2131 in Roman numerals?
MMCXXXI.
Is 2131 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 2131?
2131 is a twin prime (2129 and 2131 are both prime); the 321st prime number.