The number 31664
31664 is a composite number with 10 divisors. Its prime factorisation is × 1979. Divisors (10): 1, 2, 4, 8, 16, 1979, 3958, 7916, 15832, 31664.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31664 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31664 is composite. Its prime factorisation is
- 3
The divisors add up to 61380; without 31664 itself that is 29716, so 31664 is deficient (29716 is less than 31664). Euler's totient φ(31664) = 15824 numbers up to 31664 share no factor with it.
- 4
The digits of 31664 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31664 = 2^{4} \times 1979 \]31664 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 10 |
| Sum of divisors | 61380 |
| Euler totient φ(n) | 15824 |
| Square | 1002608896 |
| Cube | 31746608082944 |
| Square root | 177.943811 (= 4√1979) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1664 × |
31664 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand six hundred and sixty-four |
| Binary (base 2) | 111101110110000 |
| Octal (base 8) | 75660 |
| Hexadecimal (base 16) | 7BB0 |
| Base 3 | 1121102202 |
| As time | 31664 seconds = 8 h 47 min 44 s |
Is 31664 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31664 ÷ 2 = 15832) | 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 (31664 ÷ 4 = 7916) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 (31664 ÷ 8 = 3958) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | 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 31664 a prime number?
No. 31664 = × 1979, so it is divisible by 2.
What are the factors of 31664?
1, 2, 4, 8, 16, 1979, 3958, 7916, 15832, 31664.
What is 31664 in binary?
111101110110000 (hexadecimal 7BB0, octal 75660).
What is the square root of 31664?
About 177.9438, exactly 4√1979.
Is 31664 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 31664?
It is a composite number with 10 divisors.