The number 50821
50821 is the 5205th prime number. Its only divisors are 1 and 50821.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 50821: the 5205th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
50821 is prime, so its only factors are 1 and 50821. It is the 5205th prime; the next prime is 50833 and the one before is 50789.
- 3
The divisors add up to 50822; without 50821 itself that is 1, so 50821 is deficient (1 is less than 50821). Euler's totient φ(50821) = 50820 numbers up to 50821 share no factor with it.
- 4
The digits of 50821 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 109 steps to reach 1.
50821 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 50822 |
| Euler totient φ(n) | 50820 |
| Square | 2582774041 |
| Cube | 131259159537661 |
| Square root | 225.435135 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 109 |
| Scientific notation | 5.0821 × |
50821 in other forms
| Form | Value |
|---|---|
| In words | fifty thousand eight hundred and twenty-one |
| Binary (base 2) | 1100011010000101 |
| Octal (base 8) | 143205 |
| Hexadecimal (base 16) | C685 |
| Base 3 | 2120201021 |
| As time | 50821 seconds = 14 h 7 min 1 s |
Is 50821 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 5) | 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 1) | 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 50821 a prime number?
Yes. 50821 is divisible only by 1 and itself.
What are the factors of 50821?
1, 50821.
What is 50821 in binary?
1100011010000101 (hexadecimal C685, octal 143205).
What is the square root of 50821?
About 225.4351.
Is 50821 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 50821?
50821 is the 5205th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.