The number 31860
31860 is a composite number with 48 divisors. Its prime factorisation is × × 5 × 59. Divisors (48): 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45 … 31860.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31860: a Harshad number: divisible by its digit sum 18.
- 2
31860 is composite. Its prime factorisation is
- 3
The divisors add up to 100800; without 31860 itself that is 68940, so 31860 is abundant (68940 is more than 31860). Euler's totient φ(31860) = 8352 numbers up to 31860 share no factor with it.
- 4
The digits of 31860 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31860 = 2^{2} \times 3^{3} \times 5 \times 59 \]31860 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 100800 |
| Euler totient φ(n) | 8352 |
| Square | 1015059600 |
| Cube | 32339798856000 |
| Square root | 178.493697 (= 6√885) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.186 × |
31860 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and sixty |
| Binary (base 2) | 111110001110100 |
| Octal (base 8) | 76164 |
| Hexadecimal (base 16) | 7C74 |
| Base 3 | 1121201000 |
| As time | 31860 seconds = 8 h 51 min 0 s |
Is 31860 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31860 ÷ 2 = 15930) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31860 ÷ 3 = 10620) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31860 ÷ 4 = 7965) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31860 ÷ 5 = 6372) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (31860 ÷ 6 = 5310) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (31860 ÷ 9 = 3540) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (31860 ÷ 10 = 3186) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31860 ÷ 12 = 2655) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31860 a prime number?
No. 31860 = × × 5 × 59, so it is divisible by 2.
What are the factors of 31860?
1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 27, 30, 36, 45, 54, 59, 60, 90, 108, 118, 135, 177, 180, 236, 270, 295, 354, 531, 540, 590, 708, 885, 1062, 1180, 1593, 1770, 2124, 2655, 3186, 3540, 5310, 6372, 7965, 10620, 15930, 31860.
What is 31860 in binary?
111110001110100 (hexadecimal 7C74, octal 76164).
What is the square root of 31860?
About 178.4937, exactly 6√885.
Is 31860 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 31860?
31860 is a Harshad number: divisible by its digit sum 18.