The number 42861
42861 is a composite number with 16 divisors. Its prime factorisation is 3 × 7 × 13 × 157. Divisors (16): 1, 3, 7, 13, 21, 39, 91, 157, 273, 471, 1099, 2041, 3297, 6123, 14287, 42861.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42861: a Harshad number: divisible by its digit sum 21.
- 2
42861 is composite. Its prime factorisation is
- 3
The divisors add up to 70784; without 42861 itself that is 27923, so 42861 is deficient (27923 is less than 42861). Euler's totient φ(42861) = 22464 numbers up to 42861 share no factor with it.
- 4
The digits of 42861 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 194 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42861 = 3 \times 7 \times 13 \times 157 \]
42861 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 70784 |
| Euler totient φ(n) | 22464 |
| Square | 1837065321 |
| Cube | 78738456723381 |
| Square root | 207.028983 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 194 |
| Scientific notation | 4.2861 × |
42861 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand eight hundred and sixty-one |
| Binary (base 2) | 1010011101101101 |
| Octal (base 8) | 123555 |
| Hexadecimal (base 16) | A76D |
| Base 3 | 2011210110 |
| As time | 42861 seconds = 11 h 54 min 21 s |
Is 42861 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 | Yes (42861 ÷ 3 = 14287) | 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 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (42861 ÷ 7 = 6123) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42861 a prime number?
No. 42861 = 3 × 7 × 13 × 157, so it is divisible by 3.
What are the factors of 42861?
1, 3, 7, 13, 21, 39, 91, 157, 273, 471, 1099, 2041, 3297, 6123, 14287, 42861.
What is 42861 in binary?
1010011101101101 (hexadecimal A76D, octal 123555).
What is the square root of 42861?
About 207.0290.
Is 42861 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 42861?
42861 is a Harshad number: divisible by its digit sum 21.