The number 72842
72842 is a composite number with 24 divisors. Its prime factorisation is 2 × 7 × × 43. Divisors (24): 1, 2, 7, 11, 14, 22, 43, 77, 86, 121, 154, 242, 301, 473, 602, 847 … 72842.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72842 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72842 is composite. Its prime factorisation is
- 3
The divisors add up to 140448; without 72842 itself that is 67606, so 72842 is deficient (67606 is less than 72842). Euler's totient φ(72842) = 27720 numbers up to 72842 share no factor with it.
- 4
The digits of 72842 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 156 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72842 = 2 \times 7 \times 11^{2} \times 43 \]72842 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 140448 |
| Euler totient φ(n) | 27720 |
| Square | 5305956964 |
| Cube | 386496517171688 |
| Square root | 269.892571 (= 11√602) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 156 |
| Scientific notation | 7.2842 × |
72842 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand eight hundred and forty-two |
| Binary (base 2) | 10001110010001010 |
| Octal (base 8) | 216212 |
| Hexadecimal (base 16) | 11C8A |
| Base 3 | 10200220212 |
| As time | 72842 seconds = 20 h 14 min 2 s |
Is 72842 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72842 ÷ 2 = 36421) | 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 2) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (72842 ÷ 7 = 10406) | 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 2) | 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 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (72842 ÷ 11 = 6622) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72842 a prime number?
No. 72842 = 2 × 7 × × 43, so it is divisible by 2.
What are the factors of 72842?
1, 2, 7, 11, 14, 22, 43, 77, 86, 121, 154, 242, 301, 473, 602, 847, 946, 1694, 3311, 5203, 6622, 10406, 36421, 72842.
What is 72842 in binary?
10001110010001010 (hexadecimal 11C8A, octal 216212).
What is the square root of 72842?
About 269.8926, exactly 11√602.
Is 72842 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 72842?
It is a composite number with 24 divisors.