The number 21735
21735 is a composite number with 32 divisors. Its prime factorisation is × 5 × 7 × 23. Divisors (32): 1, 3, 5, 7, 9, 15, 21, 23, 27, 35, 45, 63, 69, 105, 115, 135 … 21735.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21735 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21735 is composite. Its prime factorisation is
- 3
The divisors add up to 46080; without 21735 itself that is 24345, so 21735 is abundant (24345 is more than 21735). Euler's totient φ(21735) = 9504 numbers up to 21735 share no factor with it.
- 4
The digits of 21735 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21735 = 3^{3} \times 5 \times 7 \times 23 \]21735 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 46080 |
| Euler totient φ(n) | 9504 |
| Square | 472410225 |
| Cube | 10267836240375 |
| Square root | 147.427949 (= 3√2415) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1735 × |
21735 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand seven hundred and thirty-five |
| Binary (base 2) | 101010011100111 |
| Octal (base 8) | 52347 |
| Hexadecimal (base 16) | 54E7 |
| Base 3 | 1002211000 |
| As time | 21735 seconds = 6 h 2 min 15 s |
Is 21735 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 | Yes (21735 ÷ 3 = 7245) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21735 ÷ 5 = 4347) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21735 ÷ 7 = 3105) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21735 ÷ 9 = 2415) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21735 a prime number?
No. 21735 = × 5 × 7 × 23, so it is divisible by 3.
What are the factors of 21735?
1, 3, 5, 7, 9, 15, 21, 23, 27, 35, 45, 63, 69, 105, 115, 135, 161, 189, 207, 315, 345, 483, 621, 805, 945, 1035, 1449, 2415, 3105, 4347, 7245, 21735.
What is 21735 in binary?
101010011100111 (hexadecimal 54E7, octal 52347).
What is the square root of 21735?
About 147.4279, exactly 3√2415.
Is 21735 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 21735?
It is a composite number with 32 divisors.