The number 15138
15138 is a composite number with 18 divisors. Its prime factorisation is 2 × × . Divisors (18): 1, 2, 3, 6, 9, 18, 29, 58, 87, 174, 261, 522, 841, 1682, 2523, 5046 … 15138.
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How to work it out
- 1
What is special about 15138: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
15138 is composite. Its prime factorisation is
- 3
The divisors add up to 33969; without 15138 itself that is 18831, so 15138 is abundant (18831 is more than 15138). Euler's totient φ(15138) = 4872 numbers up to 15138 share no factor with it.
- 4
The digits of 15138 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 133 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15138 = 2 \times 3^{2} \times 29^{2} \]15138 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 33969 |
| Euler totient φ(n) | 4872 |
| Square | 229159044 |
| Cube | 3469009608072 |
| Square root | 123.036580 (= 87√2) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 133 |
| Scientific notation | 1.5138 × |
15138 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand one hundred and thirty-eight |
| Binary (base 2) | 11101100100010 |
| Octal (base 8) | 35442 |
| Hexadecimal (base 16) | 3B22 |
| Base 3 | 202202200 |
| As time | 15138 seconds = 4 h 12 min 18 s |
Is 15138 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15138 ÷ 2 = 7569) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (15138 ÷ 3 = 5046) | 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 | Yes (15138 ÷ 6 = 2523) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 | Yes (15138 ÷ 9 = 1682) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15138 a prime number?
No. 15138 = 2 × × , so it is divisible by 2.
What are the factors of 15138?
1, 2, 3, 6, 9, 18, 29, 58, 87, 174, 261, 522, 841, 1682, 2523, 5046, 7569, 15138.
What is 15138 in binary?
11101100100010 (hexadecimal 3B22, octal 35442).
What is the square root of 15138?
About 123.0366, exactly 87√2.
Is 15138 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 15138?
15138 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.