The number 42001
42001 is a composite number with 4 divisors. Its prime factorisation is 97 × 433. Divisors (4): 1, 97, 433, 42001.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42001: a semiprime: 97 × 433, the product of two primes.
- 2
42001 is composite. Its prime factorisation is
- 3
The divisors add up to 42532; without 42001 itself that is 531, so 42001 is deficient (531 is less than 42001). Euler's totient φ(42001) = 41472 numbers up to 42001 share no factor with it.
- 4
The digits of 42001 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 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42001 = 97 \times 433 \]
42001 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 42532 |
| Euler totient φ(n) | 41472 |
| Square | 1764084001 |
| Cube | 74093292126001 |
| Square root | 204.941455 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 132 |
| Scientific notation | 4.2001 × |
42001 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and one |
| Binary (base 2) | 1010010000010001 |
| Octal (base 8) | 122021 |
| Hexadecimal (base 16) | A411 |
| Base 3 | 2010121121 |
| As time | 42001 seconds = 11 h 40 min 1 s |
Is 42001 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 | No (remainder 1) | 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 1) | 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 7) | 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 3) | 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 42001 a prime number?
No. 42001 = 97 × 433, so it is divisible by 97.
What are the factors of 42001?
1, 97, 433, 42001.
What is 42001 in binary?
1010010000010001 (hexadecimal A411, octal 122021).
What is the square root of 42001?
About 204.9415.
Is 42001 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 42001?
42001 is a semiprime: 97 × 433, the product of two primes.