The number 51221
51221 is a composite number with 8 divisors. Its prime factorisation is 17 × 23 × 131. Divisors (8): 1, 17, 23, 131, 391, 2227, 3013, 51221.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
51221 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
51221 is composite. Its prime factorisation is
- 3
The divisors add up to 57024; without 51221 itself that is 5803, so 51221 is deficient (5803 is less than 51221). Euler's totient φ(51221) = 45760 numbers up to 51221 share no factor with it.
- 4
The digits of 51221 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 171 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51221 = 17 \times 23 \times 131 \]
51221 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 57024 |
| Euler totient φ(n) | 45760 |
| Square | 2623590841 |
| Cube | 134382946466861 |
| Square root | 226.320569 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 171 |
| Scientific notation | 5.1221 × |
51221 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand two hundred and twenty-one |
| Binary (base 2) | 1100100000010101 |
| Octal (base 8) | 144025 |
| Hexadecimal (base 16) | C815 |
| Base 3 | 2121021002 |
| As time | 51221 seconds = 14 h 13 min 41 s |
Is 51221 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 2) | 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 5) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 51221 a prime number?
No. 51221 = 17 × 23 × 131, so it is divisible by 17.
What are the factors of 51221?
1, 17, 23, 131, 391, 2227, 3013, 51221.
What is 51221 in binary?
1100100000010101 (hexadecimal C815, octal 144025).
What is the square root of 51221?
About 226.3206.
Is 51221 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 51221?
It is a composite number with 8 divisors.