The number 72123
72123 is a composite number with 8 divisors. Its prime factorisation is 3 × 29 × 829. Divisors (8): 1, 3, 29, 87, 829, 2487, 24041, 72123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72123 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72123 is composite. Its prime factorisation is
- 3
The divisors add up to 99600; without 72123 itself that is 27477, so 72123 is deficient (27477 is less than 72123). Euler's totient φ(72123) = 46368 numbers up to 72123 share no factor with it.
- 4
The digits of 72123 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 68 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72123 = 3 \times 29 \times 829 \]
72123 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 99600 |
| Euler totient φ(n) | 46368 |
| Square | 5201727129 |
| Cube | 375164165724867 |
| Square root | 268.557256 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 68 |
| Scientific notation | 7.2123 × |
72123 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand one hundred and twenty-three |
| Binary (base 2) | 10001100110111011 |
| Octal (base 8) | 214673 |
| Hexadecimal (base 16) | 119BB |
| Base 3 | 10122221020 |
| As time | 72123 seconds = 20 h 2 min 3 s |
Is 72123 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 (72123 ÷ 3 = 24041) | 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 2) | 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 6) | 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 7) | 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 72123 a prime number?
No. 72123 = 3 × 29 × 829, so it is divisible by 3.
What are the factors of 72123?
1, 3, 29, 87, 829, 2487, 24041, 72123.
What is 72123 in binary?
10001100110111011 (hexadecimal 119BB, octal 214673).
What is the square root of 72123?
About 268.5573.
Is 72123 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 72123?
It is a composite number with 8 divisors.