The number 22155
22155 is a triangular number: 1 + 2 + … + 210 = 22155. Its prime factorisation is 3 × 5 × 7 × 211. Divisors (16): 1, 3, 5, 7, 15, 21, 35, 105, 211, 633, 1055, 1477, 3165, 4431, 7385, 22155.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 22155: a triangular number: 1 + 2 + … + 210 = 22155; a Harshad number: divisible by its digit sum 15.
- 2
22155 is composite. Its prime factorisation is
- 3
The divisors add up to 40704; without 22155 itself that is 18549, so 22155 is deficient (18549 is less than 22155). Euler's totient φ(22155) = 10080 numbers up to 22155 share no factor with it.
- 4
The digits of 22155 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 69 steps to reach 1.
LaTeX source of the formulas on this page
\[ 22155 = 3 \times 5 \times 7 \times 211 \]
22155 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 40704 |
| Euler totient φ(n) | 10080 |
| Square | 490844025 |
| Cube | 10874649373875 |
| Square root | 148.845558 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 69 |
| Scientific notation | 2.2155 × |
22155 in other forms
| Form | Value |
|---|---|
| In words | twenty-two thousand one hundred and fifty-five |
| Binary (base 2) | 101011010001011 |
| Octal (base 8) | 53213 |
| Hexadecimal (base 16) | 568B |
| Base 3 | 1010101120 |
| As time | 22155 seconds = 6 h 9 min 15 s |
Is 22155 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 (22155 ÷ 3 = 7385) | 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 | Yes (22155 ÷ 5 = 4431) | 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 | Yes (22155 ÷ 7 = 3165) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 22155 a prime number?
No. 22155 = 3 × 5 × 7 × 211, so it is divisible by 3.
What are the factors of 22155?
1, 3, 5, 7, 15, 21, 35, 105, 211, 633, 1055, 1477, 3165, 4431, 7385, 22155.
What is 22155 in binary?
101011010001011 (hexadecimal 568B, octal 53213).
What is the square root of 22155?
About 148.8456.
Is 22155 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 22155?
22155 is a triangular number: 1 + 2 + … + 210 = 22155; a Harshad number: divisible by its digit sum 15.