The number 21950
21950 is a composite number with 12 divisors. Its prime factorisation is 2 × × 439. Divisors (12): 1, 2, 5, 10, 25, 50, 439, 878, 2195, 4390, 10975, 21950.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21950 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21950 is composite. Its prime factorisation is
- 3
The divisors add up to 40920; without 21950 itself that is 18970, so 21950 is deficient (18970 is less than 21950). Euler's totient φ(21950) = 8760 numbers up to 21950 share no factor with it.
- 4
The digits of 21950 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 56 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21950 = 2 \times 5^{2} \times 439 \]21950 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 40920 |
| Euler totient φ(n) | 8760 |
| Square | 481802500 |
| Cube | 10575564875000 |
| Square root | 148.155324 (= 5√878) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 56 |
| Scientific notation | 2.195 × |
21950 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand nine hundred and fifty |
| Binary (base 2) | 101010110111110 |
| Octal (base 8) | 52676 |
| Hexadecimal (base 16) | 55BE |
| Base 3 | 1010002222 |
| As time | 21950 seconds = 6 h 5 min 50 s |
Is 21950 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21950 ÷ 2 = 10975) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21950 ÷ 5 = 4390) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21950 ÷ 10 = 2195) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21950 a prime number?
No. 21950 = 2 × × 439, so it is divisible by 2.
What are the factors of 21950?
1, 2, 5, 10, 25, 50, 439, 878, 2195, 4390, 10975, 21950.
What is 21950 in binary?
101010110111110 (hexadecimal 55BE, octal 52676).
What is the square root of 21950?
About 148.1553, exactly 5√878.
Is 21950 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 21950?
It is a composite number with 12 divisors.