The number 28738
28738 is a composite number with 4 divisors. Its prime factorisation is 2 × 14369. Divisors (4): 1, 2, 14369, 28738.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28738: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 14369, the product of two primes.
- 2
28738 is composite. Its prime factorisation is
- 3
The divisors add up to 43110; without 28738 itself that is 14372, so 28738 is deficient (14372 is less than 28738). Euler's totient φ(28738) = 14368 numbers up to 28738 share no factor with it.
- 4
The digits of 28738 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 152 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28738 = 2 \times 14369 \]
28738 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 43110 |
| Euler totient φ(n) | 14368 |
| Square | 825872644 |
| Cube | 23733928043272 |
| Square root | 169.522860 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 152 |
| Scientific notation | 2.8738 × |
28738 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand seven hundred and thirty-eight |
| Binary (base 2) | 111000001000010 |
| Octal (base 8) | 70102 |
| Hexadecimal (base 16) | 7042 |
| Base 3 | 1110102101 |
| As time | 28738 seconds = 7 h 58 min 58 s |
Is 28738 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28738 ÷ 2 = 14369) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | 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 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 1) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28738 a prime number?
No. 28738 = 2 × 14369, so it is divisible by 2.
What are the factors of 28738?
1, 2, 14369, 28738.
What is 28738 in binary?
111000001000010 (hexadecimal 7042, octal 70102).
What is the square root of 28738?
About 169.5229.
Is 28738 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 28738?
28738 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 14369, the product of two primes.