The number 31155
31155 is a composite number with 16 divisors. Its prime factorisation is 3 × 5 × 31 × 67. Divisors (16): 1, 3, 5, 15, 31, 67, 93, 155, 201, 335, 465, 1005, 2077, 6231, 10385, 31155.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31155: a Harshad number: divisible by its digit sum 15.
- 2
31155 is composite. Its prime factorisation is
- 3
The divisors add up to 52224; without 31155 itself that is 21069, so 31155 is deficient (21069 is less than 31155). Euler's totient φ(31155) = 15840 numbers up to 31155 share no factor with it.
- 4
The digits of 31155 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31155 = 3 \times 5 \times 31 \times 67 \]
31155 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 52224 |
| Euler totient φ(n) | 15840 |
| Square | 970634025 |
| Cube | 30240103048875 |
| Square root | 176.507790 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1155 × |
31155 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand one hundred and fifty-five |
| Binary (base 2) | 111100110110011 |
| Octal (base 8) | 74663 |
| Hexadecimal (base 16) | 79B3 |
| Base 3 | 1120201220 |
| As time | 31155 seconds = 8 h 39 min 15 s |
Is 31155 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 (31155 ÷ 3 = 10385) | 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 (31155 ÷ 5 = 6231) | 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 5) | 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 6) | 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 3) | 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 31155 a prime number?
No. 31155 = 3 × 5 × 31 × 67, so it is divisible by 3.
What are the factors of 31155?
1, 3, 5, 15, 31, 67, 93, 155, 201, 335, 465, 1005, 2077, 6231, 10385, 31155.
What is 31155 in binary?
111100110110011 (hexadecimal 79B3, octal 74663).
What is the square root of 31155?
About 176.5078.
Is 31155 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 31155?
31155 is a Harshad number: divisible by its digit sum 15.