The number 21588
21588 is a composite number with 24 divisors. Its prime factorisation is × 3 × 7 × 257. Divisors (24): 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 257, 514, 771, 1028 … 21588.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21588 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21588 is composite. Its prime factorisation is
- 3
The divisors add up to 57792; without 21588 itself that is 36204, so 21588 is abundant (36204 is more than 21588). Euler's totient φ(21588) = 6144 numbers up to 21588 share no factor with it.
- 4
The digits of 21588 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 118 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21588 = 2^{2} \times 3 \times 7 \times 257 \]21588 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 57792 |
| Euler totient φ(n) | 6144 |
| Square | 466041744 |
| Cube | 10060909169472 |
| Square root | 146.928554 (= 2√5397) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 118 |
| Scientific notation | 2.1588 × |
21588 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand five hundred and eighty-eight |
| Binary (base 2) | 101010001010100 |
| Octal (base 8) | 52124 |
| Hexadecimal (base 16) | 5454 |
| Base 3 | 1002121120 |
| As time | 21588 seconds = 5 h 59 min 48 s |
Is 21588 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21588 ÷ 2 = 10794) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21588 ÷ 3 = 7196) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21588 ÷ 4 = 5397) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21588 ÷ 6 = 3598) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21588 ÷ 7 = 3084) | 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 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (21588 ÷ 12 = 1799) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21588 a prime number?
No. 21588 = × 3 × 7 × 257, so it is divisible by 2.
What are the factors of 21588?
1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 257, 514, 771, 1028, 1542, 1799, 3084, 3598, 5397, 7196, 10794, 21588.
What is 21588 in binary?
101010001010100 (hexadecimal 5454, octal 52124).
What is the square root of 21588?
About 146.9286, exactly 2√5397.
Is 21588 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 21588?
It is a composite number with 24 divisors.