The number 72138
72138 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 11 × 1093. Divisors (16): 1, 2, 3, 6, 11, 22, 33, 66, 1093, 2186, 3279, 6558, 12023, 24046, 36069, 72138.
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How to work it out
- 1
72138 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
72138 is composite. Its prime factorisation is
- 3
The divisors add up to 157536; without 72138 itself that is 85398, so 72138 is abundant (85398 is more than 72138). Euler's totient φ(72138) = 21840 numbers up to 72138 share no factor with it.
- 4
The digits of 72138 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 72138 = 2 \times 3 \times 11 \times 1093 \]
72138 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 157536 |
| Euler totient φ(n) | 21840 |
| Square | 5203891044 |
| Cube | 375398292132072 |
| Square root | 268.585182 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 42 |
| Scientific notation | 7.2138 × |
72138 in other forms
| Form | Value |
|---|---|
| In words | seventy-two thousand one hundred and thirty-eight |
| Binary (base 2) | 10001100111001010 |
| Octal (base 8) | 214712 |
| Hexadecimal (base 16) | 119CA |
| Base 3 | 10122221210 |
| As time | 72138 seconds = 20 h 2 min 18 s |
Is 72138 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (72138 ÷ 2 = 36069) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (72138 ÷ 3 = 24046) | 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 (72138 ÷ 6 = 12023) | 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 3) | 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 | Yes (72138 ÷ 11 = 6558) | 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 72138 a prime number?
No. 72138 = 2 × 3 × 11 × 1093, so it is divisible by 2.
What are the factors of 72138?
1, 2, 3, 6, 11, 22, 33, 66, 1093, 2186, 3279, 6558, 12023, 24046, 36069, 72138.
What is 72138 in binary?
10001100111001010 (hexadecimal 119CA, octal 214712).
What is the square root of 72138?
About 268.5852.
Is 72138 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 72138?
It is a composite number with 16 divisors.