The number 31120
31120 is a composite number with 20 divisors. Its prime factorisation is × 5 × 389. Divisors (20): 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 389, 778, 1556, 1945, 3112, 3890 … 31120.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31120 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31120 is composite. Its prime factorisation is
- 3
The divisors add up to 72540; without 31120 itself that is 41420, so 31120 is abundant (41420 is more than 31120). Euler's totient φ(31120) = 12416 numbers up to 31120 share no factor with it.
- 4
The digits of 31120 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 41 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31120 = 2^{4} \times 5 \times 389 \]31120 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 20 |
| Sum of divisors | 72540 |
| Euler totient φ(n) | 12416 |
| Square | 968454400 |
| Cube | 30138300928000 |
| Square root | 176.408617 (= 4√1945) |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 41 |
| Scientific notation | 3.112 × |
31120 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand one hundred and twenty |
| Binary (base 2) | 111100110010000 |
| Octal (base 8) | 74620 |
| Hexadecimal (base 16) | 7990 |
| Base 3 | 1120200121 |
| As time | 31120 seconds = 8 h 38 min 40 s |
Is 31120 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31120 ÷ 2 = 15560) | 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 | Yes (31120 ÷ 4 = 7780) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31120 ÷ 5 = 6224) | 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 5) | 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 (31120 ÷ 8 = 3890) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (31120 ÷ 10 = 3112) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31120 a prime number?
No. 31120 = × 5 × 389, so it is divisible by 2.
What are the factors of 31120?
1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 389, 778, 1556, 1945, 3112, 3890, 6224, 7780, 15560, 31120.
What is 31120 in binary?
111100110010000 (hexadecimal 7990, octal 74620).
What is the square root of 31120?
About 176.4086, exactly 4√1945.
Is 31120 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 31120?
It is a composite number with 20 divisors.