The number 42724
42724 is a palindrome: it reads 42724 backwards too. Its prime factorisation is × 11 × 971. Divisors (12): 1, 2, 4, 11, 22, 44, 971, 1942, 3884, 10681, 21362, 42724.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42724: a palindrome: it reads 42724 backwards too.
- 2
42724 is composite. Its prime factorisation is
- 3
The divisors add up to 81648; without 42724 itself that is 38924, so 42724 is deficient (38924 is less than 42724). Euler's totient φ(42724) = 19400 numbers up to 42724 share no factor with it.
- 4
The digits of 42724 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42724 = 2^{2} \times 11 \times 971 \]42724 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 81648 |
| Euler totient φ(n) | 19400 |
| Square | 1825340176 |
| Cube | 77985833679424 |
| Square root | 206.697847 (= 2√10681) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.2724 × |
42724 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and twenty-four |
| Binary (base 2) | 1010011011100100 |
| Octal (base 8) | 123344 |
| Hexadecimal (base 16) | A6E4 |
| Base 3 | 2011121101 |
| As time | 42724 seconds = 11 h 52 min 4 s |
Is 42724 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42724 ÷ 2 = 21362) | 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 (42724 ÷ 4 = 10681) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 3) | 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 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (42724 ÷ 11 = 3884) | 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 42724 a prime number?
No. 42724 = × 11 × 971, so it is divisible by 2.
What are the factors of 42724?
1, 2, 4, 11, 22, 44, 971, 1942, 3884, 10681, 21362, 42724.
What is 42724 in binary?
1010011011100100 (hexadecimal A6E4, octal 123344).
What is the square root of 42724?
About 206.6978, exactly 2√10681.
Is 42724 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 42724?
42724 is a palindrome: it reads 42724 backwards too.