The number 21460
21460 is a composite number with 24 divisors. Its prime factorisation is × 5 × 29 × 37. Divisors (24): 1, 2, 4, 5, 10, 20, 29, 37, 58, 74, 116, 145, 148, 185, 290, 370 … 21460.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21460 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21460 is composite. Its prime factorisation is
- 3
The divisors add up to 47880; without 21460 itself that is 26420, so 21460 is abundant (26420 is more than 21460). Euler's totient φ(21460) = 8064 numbers up to 21460 share no factor with it.
- 4
The digits of 21460 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 74 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21460 = 2^{2} \times 5 \times 29 \times 37 \]21460 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 47880 |
| Euler totient φ(n) | 8064 |
| Square | 460531600 |
| Cube | 9883008136000 |
| Square root | 146.492321 (= 2√5365) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 74 |
| Scientific notation | 2.146 × |
21460 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and sixty |
| Binary (base 2) | 101001111010100 |
| Octal (base 8) | 51724 |
| Hexadecimal (base 16) | 53D4 |
| Base 3 | 1002102211 |
| As time | 21460 seconds = 5 h 57 min 40 s |
Is 21460 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21460 ÷ 2 = 10730) | 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 | Yes (21460 ÷ 4 = 5365) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21460 ÷ 5 = 4292) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21460 ÷ 10 = 2146) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21460 a prime number?
No. 21460 = × 5 × 29 × 37, so it is divisible by 2.
What are the factors of 21460?
1, 2, 4, 5, 10, 20, 29, 37, 58, 74, 116, 145, 148, 185, 290, 370, 580, 740, 1073, 2146, 4292, 5365, 10730, 21460.
What is 21460 in binary?
101001111010100 (hexadecimal 53D4, octal 51724).
What is the square root of 21460?
About 146.4923, exactly 2√5365.
Is 21460 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 21460?
It is a composite number with 24 divisors.