The number 72428
72428 is a composite number with 12 divisors. Its prime factorisation is × 19 × 953. Divisors (12): 1, 2, 4, 19, 38, 76, 953, 1906, 3812, 18107, 36214, 72428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
72428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72428 is composite. Its prime factorisation is
- 3
The divisors add up to 133560; without 72428 itself that is 61132, so 72428 is deficient (61132 is less than 72428). Euler's totient φ(72428) = 34272 numbers up to 72428 share no factor with it.
- 4
The digits of 72428 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 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72428 = 2^{2} \times 19 \times 953 \]72428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 133560 |
| Euler totient φ(n) | 34272 |
| Square | 5245815184 |
| Cube | 379943902146752 |
| Square root | 269.124507 (= 2√18107) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.2428 × |
72428 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand four hundred and twenty-eight |
| Binary (base 2) | 10001101011101100 |
| Octal (base 8) | 215354 |
| Hexadecimal (base 16) | 11AEC |
| Base 3 | 10200100112 |
| As time | 72428 seconds = 20 h 7 min 8 s |
Is 72428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72428 ÷ 2 = 36214) | 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 | Yes (72428 ÷ 4 = 18107) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 72428 a prime number?
No. 72428 = × 19 × 953, so it is divisible by 2.
What are the factors of 72428?
1, 2, 4, 19, 38, 76, 953, 1906, 3812, 18107, 36214, 72428.
What is 72428 in binary?
10001101011101100 (hexadecimal 11AEC, octal 215354).
What is the square root of 72428?
About 269.1245, exactly 2√18107.
Is 72428 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 72428?
It is a composite number with 12 divisors.