The number 556
556 is a composite number with 6 divisors. Its prime factorisation is × 139. Divisors (6): 1, 2, 4, 139, 278, 556.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 556: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
556 is composite. Its prime factorisation is
- 3
The divisors add up to 980; without 556 itself that is 424, so 556 is deficient (424 is less than 556). Euler's totient φ(556) = 276 numbers up to 556 share no factor with it.
- 4
The digits of 556 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 556 = 2^{2} \times 139 \]556 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 980 |
| Euler totient φ(n) | 276 |
| Square | 309136 |
| Cube | 171879616 |
| Square root | 23.579652 (= 2√139) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 43 |
| Scientific notation | 5.56 × |
556 in other forms
| Form | Value |
|---|---|
| In words | five hundred and fifty-six |
| Roman numerals | DLVI |
| Binary (base 2) | 1000101100 |
| Octal (base 8) | 1054 |
| Hexadecimal (base 16) | 22C |
| Base 3 | 202121 |
| As time | 556 seconds = 9 min 16 s |
Is 556 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (556 ÷ 2 = 278) | 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 | Yes (556 ÷ 4 = 139) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 6) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 556 a prime number?
No. 556 = × 139, so it is divisible by 2.
What are the factors of 556?
1, 2, 4, 139, 278, 556.
What is 556 in binary?
1000101100 (hexadecimal 22C, octal 1054).
What is the square root of 556?
About 23.5797, exactly 2√139.
What is 556 in Roman numerals?
DLVI.
Is 556 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 556?
556 is a happy number: repeatedly adding the squares of its digits reaches 1.