The number 31275
31275 is a composite number with 18 divisors. Its prime factorisation is × × 139. Divisors (18): 1, 3, 5, 9, 15, 25, 45, 75, 139, 225, 417, 695, 1251, 2085, 3475, 6255 … 31275.
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How to work it out
- 1
31275 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31275 is composite. Its prime factorisation is
- 3
The divisors add up to 56420; without 31275 itself that is 25145, so 31275 is deficient (25145 is less than 31275). Euler's totient φ(31275) = 16560 numbers up to 31275 share no factor with it.
- 4
The digits of 31275 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 41 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31275 = 3^{2} \times 5^{2} \times 139 \]31275 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 56420 |
| Euler totient φ(n) | 16560 |
| Square | 978125625 |
| Cube | 30590878921875 |
| Square root | 176.847392 (= 15√139) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 41 |
| Scientific notation | 3.1275 × |
31275 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand two hundred and seventy-five |
| Binary (base 2) | 111101000101011 |
| Octal (base 8) | 75053 |
| Hexadecimal (base 16) | 7A2B |
| Base 3 | 1120220100 |
| As time | 31275 seconds = 8 h 41 min 15 s |
Is 31275 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 | Yes (31275 ÷ 3 = 10425) | 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 | Yes (31275 ÷ 5 = 6255) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (31275 ÷ 9 = 3475) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31275 a prime number?
No. 31275 = × × 139, so it is divisible by 3.
What are the factors of 31275?
1, 3, 5, 9, 15, 25, 45, 75, 139, 225, 417, 695, 1251, 2085, 3475, 6255, 10425, 31275.
What is 31275 in binary?
111101000101011 (hexadecimal 7A2B, octal 75053).
What is the square root of 31275?
About 176.8474, exactly 15√139.
Is 31275 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 31275?
It is a composite number with 18 divisors.