The number 72443
72443 is a composite number with 8 divisors. Its prime factorisation is 7 × 79 × 131. Divisors (8): 1, 7, 79, 131, 553, 917, 10349, 72443.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72443: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
72443 is composite. Its prime factorisation is
- 3
The divisors add up to 84480; without 72443 itself that is 12037, so 72443 is deficient (12037 is less than 72443). Euler's totient φ(72443) = 60840 numbers up to 72443 share no factor with it.
- 4
The digits of 72443 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 156 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72443 = 7 \times 79 \times 131 \]
72443 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 84480 |
| Euler totient φ(n) | 60840 |
| Square | 5247988249 |
| Cube | 380180012722307 |
| Square root | 269.152373 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 156 |
| Scientific notation | 7.2443 × |
72443 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand four hundred and forty-three |
| Binary (base 2) | 10001101011111011 |
| Octal (base 8) | 215373 |
| Hexadecimal (base 16) | 11AFB |
| Base 3 | 10200101002 |
| As time | 72443 seconds = 20 h 7 min 23 s |
Is 72443 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 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 | Yes (72443 ÷ 7 = 10349) | 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 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72443 a prime number?
No. 72443 = 7 × 79 × 131, so it is divisible by 7.
What are the factors of 72443?
1, 7, 79, 131, 553, 917, 10349, 72443.
What is 72443 in binary?
10001101011111011 (hexadecimal 11AFB, octal 215373).
What is the square root of 72443?
About 269.1524.
Is 72443 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 72443?
72443 is a happy number: repeatedly adding the squares of its digits reaches 1.