The number 31969
31969 is a composite number with 4 divisors. Its prime factorisation is 7 × 4567. Divisors (4): 1, 7, 4567, 31969.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31969: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 4567, the product of two primes.
- 2
31969 is composite. Its prime factorisation is
- 3
The divisors add up to 36544; without 31969 itself that is 4575, so 31969 is deficient (4575 is less than 31969). Euler's totient φ(31969) = 27396 numbers up to 31969 share no factor with it.
- 4
The digits of 31969 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31969 = 7 \times 4567 \]
31969 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 36544 |
| Euler totient φ(n) | 27396 |
| Square | 1022016961 |
| Cube | 32672860226209 |
| Square root | 178.798770 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1969 × |
31969 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and sixty-nine |
| Binary (base 2) | 111110011100001 |
| Octal (base 8) | 76341 |
| Hexadecimal (base 16) | 7CE1 |
| Base 3 | 1121212001 |
| As time | 31969 seconds = 8 h 52 min 49 s |
Is 31969 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 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (31969 ÷ 7 = 4567) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31969 a prime number?
No. 31969 = 7 × 4567, so it is divisible by 7.
What are the factors of 31969?
1, 7, 4567, 31969.
What is 31969 in binary?
111110011100001 (hexadecimal 7CE1, octal 76341).
What is the square root of 31969?
About 178.7988.
Is 31969 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 31969?
31969 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 4567, the product of two primes.