The number 50721
50721 is a triangular number: 1 + 2 + … + 318 = 50721. Its prime factorisation is 3 × 11 × 29 × 53. Divisors (16): 1, 3, 11, 29, 33, 53, 87, 159, 319, 583, 957, 1537, 1749, 4611, 16907, 50721.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 50721: a triangular number: 1 + 2 + … + 318 = 50721; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
50721 is composite. Its prime factorisation is
- 3
The divisors add up to 77760; without 50721 itself that is 27039, so 50721 is deficient (27039 is less than 50721). Euler's totient φ(50721) = 29120 numbers up to 50721 share no factor with it.
- 4
The digits of 50721 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 50721 = 3 \times 11 \times 29 \times 53 \]
50721 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 77760 |
| Euler totient φ(n) | 29120 |
| Square | 2572619841 |
| Cube | 130485850955361 |
| Square root | 225.213232 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 57 |
| Scientific notation | 5.0721 × |
50721 in other forms
| Form | Value |
|---|---|
| In words | fifty thousand seven hundred and twenty-one |
| Binary (base 2) | 1100011000100001 |
| Octal (base 8) | 143041 |
| Hexadecimal (base 16) | C621 |
| Base 3 | 2120120120 |
| As time | 50721 seconds = 14 h 5 min 21 s |
Is 50721 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 (50721 ÷ 3 = 16907) | 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 | No (remainder 6) | 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 6) | 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 | Yes (50721 ÷ 11 = 4611) | 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 50721 a prime number?
No. 50721 = 3 × 11 × 29 × 53, so it is divisible by 3.
What are the factors of 50721?
1, 3, 11, 29, 33, 53, 87, 159, 319, 583, 957, 1537, 1749, 4611, 16907, 50721.
What is 50721 in binary?
1100011000100001 (hexadecimal C621, octal 143041).
What is the square root of 50721?
About 225.2132.
Is 50721 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 50721?
50721 is a triangular number: 1 + 2 + … + 318 = 50721; a happy number: repeatedly adding the squares of its digits reaches 1.