The number 31874
31874 is a composite number with 4 divisors. Its prime factorisation is 2 × 15937. Divisors (4): 1, 2, 15937, 31874.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31874: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 15937, the product of two primes.
- 2
31874 is composite. Its prime factorisation is
- 3
The divisors add up to 47814; without 31874 itself that is 15940, so 31874 is deficient (15940 is less than 31874). Euler's totient φ(31874) = 15936 numbers up to 31874 share no factor with it.
- 4
The digits of 31874 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31874 = 2 \times 15937 \]
31874 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 47814 |
| Euler totient φ(n) | 15936 |
| Square | 1015951876 |
| Cube | 32382450095624 |
| Square root | 178.532910 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1874 × |
31874 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and seventy-four |
| Binary (base 2) | 111110010000010 |
| Octal (base 8) | 76202 |
| Hexadecimal (base 16) | 7C82 |
| Base 3 | 1121201112 |
| As time | 31874 seconds = 8 h 51 min 14 s |
Is 31874 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31874 ÷ 2 = 15937) | 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 | No (remainder 2) | 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 | No (remainder 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31874 a prime number?
No. 31874 = 2 × 15937, so it is divisible by 2.
What are the factors of 31874?
1, 2, 15937, 31874.
What is 31874 in binary?
111110010000010 (hexadecimal 7C82, octal 76202).
What is the square root of 31874?
About 178.5329.
Is 31874 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 31874?
31874 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 15937, the product of two primes.