The number 21677
21677 is a composite number with 4 divisors. Its prime factorisation is 53 × 409. Divisors (4): 1, 53, 409, 21677.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21677: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 53 × 409, the product of two primes.
- 2
21677 is composite. Its prime factorisation is
- 3
The divisors add up to 22140; without 21677 itself that is 463, so 21677 is deficient (463 is less than 21677). Euler's totient φ(21677) = 21216 numbers up to 21677 share no factor with it.
- 4
The digits of 21677 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21677 = 53 \times 409 \]
21677 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 22140 |
| Euler totient φ(n) | 21216 |
| Square | 469892329 |
| Cube | 10185856015733 |
| Square root | 147.231111 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.1677 × |
21677 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand six hundred and seventy-seven |
| Binary (base 2) | 101010010101101 |
| Octal (base 8) | 52255 |
| Hexadecimal (base 16) | 54AD |
| Base 3 | 1002201212 |
| As time | 21677 seconds = 6 h 1 min 17 s |
Is 21677 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 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21677 a prime number?
No. 21677 = 53 × 409, so it is divisible by 53.
What are the factors of 21677?
1, 53, 409, 21677.
What is 21677 in binary?
101010010101101 (hexadecimal 54AD, octal 52255).
What is the square root of 21677?
About 147.2311.
Is 21677 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 21677?
21677 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 53 × 409, the product of two primes.