The number 31978
31978 is a composite number with 8 divisors. Its prime factorisation is 2 × 59 × 271. Divisors (8): 1, 2, 59, 118, 271, 542, 15989, 31978.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31978 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31978 is composite. Its prime factorisation is
- 3
The divisors add up to 48960; without 31978 itself that is 16982, so 31978 is deficient (16982 is less than 31978). Euler's totient φ(31978) = 15660 numbers up to 31978 share no factor with it.
- 4
The digits of 31978 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 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31978 = 2 \times 59 \times 271 \]
31978 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 48960 |
| Euler totient φ(n) | 15660 |
| Square | 1022592484 |
| Cube | 32700462453352 |
| Square root | 178.823936 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1978 × |
31978 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and seventy-eight |
| Binary (base 2) | 111110011101010 |
| Octal (base 8) | 76352 |
| Hexadecimal (base 16) | 7CEA |
| Base 3 | 1121212101 |
| As time | 31978 seconds = 8 h 52 min 58 s |
Is 31978 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31978 ÷ 2 = 15989) | 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 2) | 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 4) | 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 2) | 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 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31978 a prime number?
No. 31978 = 2 × 59 × 271, so it is divisible by 2.
What are the factors of 31978?
1, 2, 59, 118, 271, 542, 15989, 31978.
What is 31978 in binary?
111110011101010 (hexadecimal 7CEA, octal 76352).
What is the square root of 31978?
About 178.8239.
Is 31978 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 31978?
It is a composite number with 8 divisors.