The number 31328
31328 is a composite number with 24 divisors. Its prime factorisation is × 11 × 89. Divisors (24): 1, 2, 4, 8, 11, 16, 22, 32, 44, 88, 89, 176, 178, 352, 356, 712 … 31328.
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How to work it out
- 1
31328 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31328 is composite. Its prime factorisation is
- 3
The divisors add up to 68040; without 31328 itself that is 36712, so 31328 is abundant (36712 is more than 31328). Euler's totient φ(31328) = 14080 numbers up to 31328 share no factor with it.
- 4
The digits of 31328 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31328 = 2^{5} \times 11 \times 89 \]31328 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 68040 |
| Euler totient φ(n) | 14080 |
| Square | 981443584 |
| Cube | 30746664599552 |
| Square root | 176.997175 (= 4√1958) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1328 × |
31328 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand three hundred and twenty-eight |
| Binary (base 2) | 111101001100000 |
| Octal (base 8) | 75140 |
| Hexadecimal (base 16) | 7A60 |
| Base 3 | 1120222022 |
| As time | 31328 seconds = 8 h 42 min 8 s |
Is 31328 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31328 ÷ 2 = 15664) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31328 ÷ 4 = 7832) | 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 2) | 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 | Yes (31328 ÷ 8 = 3916) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (31328 ÷ 11 = 2848) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31328 a prime number?
No. 31328 = × 11 × 89, so it is divisible by 2.
What are the factors of 31328?
1, 2, 4, 8, 11, 16, 22, 32, 44, 88, 89, 176, 178, 352, 356, 712, 979, 1424, 1958, 2848, 3916, 7832, 15664, 31328.
What is 31328 in binary?
111101001100000 (hexadecimal 7A60, octal 75140).
What is the square root of 31328?
About 176.9972, exactly 4√1958.
Is 31328 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 31328?
It is a composite number with 24 divisors.