The number 21494
21494 is a composite number with 8 divisors. Its prime factorisation is 2 × 11 × 977. Divisors (8): 1, 2, 11, 22, 977, 1954, 10747, 21494.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21494 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21494 is composite. Its prime factorisation is
- 3
The divisors add up to 35208; without 21494 itself that is 13714, so 21494 is deficient (13714 is less than 21494). Euler's totient φ(21494) = 9760 numbers up to 21494 share no factor with it.
- 4
The digits of 21494 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21494 = 2 \times 11 \times 977 \]
21494 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 35208 |
| Euler totient φ(n) | 9760 |
| Square | 461992036 |
| Cube | 9930056821784 |
| Square root | 146.608322 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.1494 × |
21494 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and ninety-four |
| Binary (base 2) | 101001111110110 |
| Octal (base 8) | 51766 |
| Hexadecimal (base 16) | 53F6 |
| Base 3 | 1002111002 |
| As time | 21494 seconds = 5 h 58 min 14 s |
Is 21494 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21494 ÷ 2 = 10747) | 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 | No (remainder 4) | 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 4) | 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 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21494 ÷ 11 = 1954) | 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 21494 a prime number?
No. 21494 = 2 × 11 × 977, so it is divisible by 2.
What are the factors of 21494?
1, 2, 11, 22, 977, 1954, 10747, 21494.
What is 21494 in binary?
101001111110110 (hexadecimal 53F6, octal 51766).
What is the square root of 21494?
About 146.6083.
Is 21494 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 21494?
It is a composite number with 8 divisors.