The number 72423
72423 is a composite number with 12 divisors. Its prime factorisation is × 13 × 619. Divisors (12): 1, 3, 9, 13, 39, 117, 619, 1857, 5571, 8047, 24141, 72423.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 72423: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
72423 is composite. Its prime factorisation is
- 3
The divisors add up to 112840; without 72423 itself that is 40417, so 72423 is deficient (40417 is less than 72423). Euler's totient φ(72423) = 44496 numbers up to 72423 share no factor with it.
- 4
The digits of 72423 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72423 = 3^{2} \times 13 \times 619 \]72423 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 112840 |
| Euler totient φ(n) | 44496 |
| Square | 5245090929 |
| Cube | 379865220350967 |
| Square root | 269.115217 (= 3√8047) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.2423 × |
72423 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand four hundred and twenty-three |
| Binary (base 2) | 10001101011100111 |
| Octal (base 8) | 215347 |
| Hexadecimal (base 16) | 11AE7 |
| Base 3 | 10200100100 |
| As time | 72423 seconds = 20 h 7 min 3 s |
Is 72423 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 | Yes (72423 ÷ 3 = 24141) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (72423 ÷ 9 = 8047) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72423 a prime number?
No. 72423 = × 13 × 619, so it is divisible by 3.
What are the factors of 72423?
1, 3, 9, 13, 39, 117, 619, 1857, 5571, 8047, 24141, 72423.
What is 72423 in binary?
10001101011100111 (hexadecimal 11AE7, octal 215347).
What is the square root of 72423?
About 269.1152, exactly 3√8047.
Is 72423 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 72423?
72423 is a happy number: repeatedly adding the squares of its digits reaches 1.