The number 21435
21435 is a composite number with 8 divisors. Its prime factorisation is 3 × 5 × 1429. Divisors (8): 1, 3, 5, 15, 1429, 4287, 7145, 21435.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21435: a Harshad number: divisible by its digit sum 15.
- 2
21435 is composite. Its prime factorisation is
- 3
The divisors add up to 34320; without 21435 itself that is 12885, so 21435 is deficient (12885 is less than 21435). Euler's totient φ(21435) = 11424 numbers up to 21435 share no factor with it.
- 4
The digits of 21435 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21435 = 3 \times 5 \times 1429 \]
21435 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 34320 |
| Euler totient φ(n) | 11424 |
| Square | 459459225 |
| Cube | 9848508487875 |
| Square root | 146.406967 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1435 × |
21435 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and thirty-five |
| Binary (base 2) | 101001110111011 |
| Octal (base 8) | 51673 |
| Hexadecimal (base 16) | 53BB |
| Base 3 | 1002101220 |
| As time | 21435 seconds = 5 h 57 min 15 s |
Is 21435 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 (21435 ÷ 3 = 7145) | 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 (21435 ÷ 5 = 4287) | 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 | No (remainder 1) | 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 3) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 21435 a prime number?
No. 21435 = 3 × 5 × 1429, so it is divisible by 3.
What are the factors of 21435?
1, 3, 5, 15, 1429, 4287, 7145, 21435.
What is 21435 in binary?
101001110111011 (hexadecimal 53BB, octal 51673).
What is the square root of 21435?
About 146.4070.
Is 21435 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 21435?
21435 is a Harshad number: divisible by its digit sum 15.