The number 31951
31951 is a composite number with 4 divisors. Its prime factorisation is 89 × 359. Divisors (4): 1, 89, 359, 31951.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31951: a semiprime: 89 × 359, the product of two primes.
- 2
31951 is composite. Its prime factorisation is
- 3
The divisors add up to 32400; without 31951 itself that is 449, so 31951 is deficient (449 is less than 31951). Euler's totient φ(31951) = 31504 numbers up to 31951 share no factor with it.
- 4
The digits of 31951 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 98 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31951 = 89 \times 359 \]
31951 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 32400 |
| Euler totient φ(n) | 31504 |
| Square | 1020866401 |
| Cube | 32617702378351 |
| Square root | 178.748427 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 98 |
| Scientific notation | 3.1951 × |
31951 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and fifty-one |
| Binary (base 2) | 111110011001111 |
| Octal (base 8) | 76317 |
| Hexadecimal (base 16) | 7CCF |
| Base 3 | 1121211101 |
| As time | 31951 seconds = 8 h 52 min 31 s |
Is 31951 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 7) | 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 7) | 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 31951 a prime number?
No. 31951 = 89 × 359, so it is divisible by 89.
What are the factors of 31951?
1, 89, 359, 31951.
What is 31951 in binary?
111110011001111 (hexadecimal 7CCF, octal 76317).
What is the square root of 31951?
About 178.7484.
Is 31951 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31951?
31951 is a semiprime: 89 × 359, the product of two primes.