The number 31123
31123 is a twin prime (31121 and 31123 are both prime) and the 3352nd prime number. Its only divisors are 1 and 31123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31123: a twin prime (31121 and 31123 are both prime); the 3352nd prime number.
- 2
31123 is prime, so its only factors are 1 and 31123. It is the 3352nd prime; the next prime is 31139 and the one before is 31121.
- 3
The divisors add up to 31124; without 31123 itself that is 1, so 31123 is deficient (1 is less than 31123). Euler's totient φ(31123) = 31122 numbers up to 31123 share no factor with it.
- 4
The digits of 31123 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 85 steps to reach 1.
31123 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31124 |
| Euler totient φ(n) | 31122 |
| Square | 968641129 |
| Cube | 30147017857867 |
| Square root | 176.417119 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1123 × |
31123 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand one hundred and twenty-three |
| Binary (base 2) | 111100110010011 |
| Octal (base 8) | 74623 |
| Hexadecimal (base 16) | 7993 |
| Base 3 | 1120200201 |
| As time | 31123 seconds = 8 h 38 min 43 s |
Is 31123 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 3) | 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 3) | 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 3) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31123 a prime number?
Yes. 31123 is divisible only by 1 and itself.
What are the factors of 31123?
1, 31123.
What is 31123 in binary?
111100110010011 (hexadecimal 7993, octal 74623).
What is the square root of 31123?
About 176.4171.
Is 31123 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 31123?
31123 is a twin prime (31121 and 31123 are both prime); the 3352nd prime number.