The number 42751
42751 is the 4471st prime number. Its only divisors are 1 and 42751.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42751: the 4471st prime number.
- 2
42751 is prime, so its only factors are 1 and 42751. It is the 4471st prime; the next prime is 42767 and the one before is 42743.
- 3
The divisors add up to 42752; without 42751 itself that is 1, so 42751 is deficient (1 is less than 42751). Euler's totient φ(42751) = 42750 numbers up to 42751 share no factor with it.
- 4
The digits of 42751 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 181 steps to reach 1.
42751 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 42752 |
| Euler totient φ(n) | 42750 |
| Square | 1827648001 |
| Cube | 78133779690751 |
| Square root | 206.763150 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 181 |
| Scientific notation | 4.2751 × |
42751 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and fifty-one |
| Binary (base 2) | 1010011011111111 |
| Octal (base 8) | 123377 |
| Hexadecimal (base 16) | A6FF |
| Base 3 | 2011122101 |
| As time | 42751 seconds = 11 h 52 min 31 s |
Is 42751 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 3) | 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 2) | 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 7) | 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 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42751 a prime number?
Yes. 42751 is divisible only by 1 and itself.
What are the factors of 42751?
1, 42751.
What is 42751 in binary?
1010011011111111 (hexadecimal A6FF, octal 123377).
What is the square root of 42751?
About 206.7631.
Is 42751 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 42751?
42751 is the 4471st prime number.