The number 21340
21340 is a composite number with 24 divisors. Its prime factorisation is × 5 × 11 × 97. Divisors (24): 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 97, 110, 194, 220, 388, 485 … 21340.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21340: a Harshad number: divisible by its digit sum 10.
- 2
21340 is composite. Its prime factorisation is
- 3
The divisors add up to 49392; without 21340 itself that is 28052, so 21340 is abundant (28052 is more than 21340). Euler's totient φ(21340) = 7680 numbers up to 21340 share no factor with it.
- 4
The digits of 21340 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21340 = 2^{2} \times 5 \times 11 \times 97 \]21340 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 49392 |
| Euler totient φ(n) | 7680 |
| Square | 455395600 |
| Cube | 9718142104000 |
| Square root | 146.082169 (= 2√5335) |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 48 |
| Scientific notation | 2.134 × |
21340 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and forty |
| Binary (base 2) | 101001101011100 |
| Octal (base 8) | 51534 |
| Hexadecimal (base 16) | 535C |
| Base 3 | 1002021101 |
| As time | 21340 seconds = 5 h 55 min 40 s |
Is 21340 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21340 ÷ 2 = 10670) | 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 (21340 ÷ 4 = 5335) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21340 ÷ 5 = 4268) | 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 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21340 ÷ 10 = 2134) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21340 ÷ 11 = 1940) | 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 21340 a prime number?
No. 21340 = × 5 × 11 × 97, so it is divisible by 2.
What are the factors of 21340?
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 97, 110, 194, 220, 388, 485, 970, 1067, 1940, 2134, 4268, 5335, 10670, 21340.
What is 21340 in binary?
101001101011100 (hexadecimal 535C, octal 51534).
What is the square root of 21340?
About 146.0822, exactly 2√5335.
Is 21340 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 21340?
21340 is a Harshad number: divisible by its digit sum 10.