The number 31908
31908 is a composite number with 12 divisors. Its prime factorisation is × 3 × 2659. Divisors (12): 1, 2, 3, 4, 6, 12, 2659, 5318, 7977, 10636, 15954, 31908.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31908 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31908 is composite. Its prime factorisation is
- 3
The divisors add up to 74480; without 31908 itself that is 42572, so 31908 is abundant (42572 is more than 31908). Euler's totient φ(31908) = 10632 numbers up to 31908 share no factor with it.
- 4
The digits of 31908 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31908 = 2^{2} \times 3 \times 2659 \]31908 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 74480 |
| Euler totient φ(n) | 10632 |
| Square | 1018120464 |
| Cube | 32486187765312 |
| Square root | 178.628105 (= 2√7977) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1908 × |
31908 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and eight |
| Binary (base 2) | 111110010100100 |
| Octal (base 8) | 76244 |
| Hexadecimal (base 16) | 7CA4 |
| Base 3 | 1121202210 |
| As time | 31908 seconds = 8 h 51 min 48 s |
Is 31908 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31908 ÷ 2 = 15954) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31908 ÷ 3 = 10636) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31908 ÷ 4 = 7977) | 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 | Yes (31908 ÷ 6 = 5318) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31908 ÷ 12 = 2659) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31908 a prime number?
No. 31908 = × 3 × 2659, so it is divisible by 2.
What are the factors of 31908?
1, 2, 3, 4, 6, 12, 2659, 5318, 7977, 10636, 15954, 31908.
What is 31908 in binary?
111110010100100 (hexadecimal 7CA4, octal 76244).
What is the square root of 31908?
About 178.6281, exactly 2√7977.
Is 31908 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 31908?
It is a composite number with 12 divisors.