The number 42985
42985 is a composite number with 4 divisors. Its prime factorisation is 5 × 8597. Divisors (4): 1, 5, 8597, 42985.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42985: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 5 × 8597, the product of two primes.
- 2
42985 is composite. Its prime factorisation is
- 3
The divisors add up to 51588; without 42985 itself that is 8603, so 42985 is deficient (8603 is less than 42985). Euler's totient φ(42985) = 34384 numbers up to 42985 share no factor with it.
- 4
The digits of 42985 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 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42985 = 5 \times 8597 \]
42985 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 51588 |
| Euler totient φ(n) | 34384 |
| Square | 1847710225 |
| Cube | 79423824021625 |
| Square root | 207.328242 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 132 |
| Scientific notation | 4.2985 × |
42985 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand nine hundred and eighty-five |
| Binary (base 2) | 1010011111101001 |
| Octal (base 8) | 123751 |
| Hexadecimal (base 16) | A7E9 |
| Base 3 | 2011222001 |
| As time | 42985 seconds = 11 h 56 min 25 s |
Is 42985 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 | No (remainder 1) | 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 | Yes (42985 ÷ 5 = 8597) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 | No (remainder 1) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42985 a prime number?
No. 42985 = 5 × 8597, so it is divisible by 5.
What are the factors of 42985?
1, 5, 8597, 42985.
What is 42985 in binary?
1010011111101001 (hexadecimal A7E9, octal 123751).
What is the square root of 42985?
About 207.3282.
Is 42985 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 42985?
42985 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 5 × 8597, the product of two primes.