The number 31555
31555 is a composite number with 4 divisors. Its prime factorisation is 5 × 6311. Divisors (4): 1, 5, 6311, 31555.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31555: a semiprime: 5 × 6311, the product of two primes.
- 2
31555 is composite. Its prime factorisation is
- 3
The divisors add up to 37872; without 31555 itself that is 6317, so 31555 is deficient (6317 is less than 31555). Euler's totient φ(31555) = 25240 numbers up to 31555 share no factor with it.
- 4
The digits of 31555 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31555 = 5 \times 6311 \]
31555 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 37872 |
| Euler totient φ(n) | 25240 |
| Square | 995718025 |
| Cube | 31419882278875 |
| Square root | 177.637271 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 103 |
| Scientific notation | 3.1555 × |
31555 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand five hundred and fifty-five |
| Binary (base 2) | 111101101000011 |
| Octal (base 8) | 75503 |
| Hexadecimal (base 16) | 7B43 |
| Base 3 | 1121021201 |
| As time | 31555 seconds = 8 h 45 min 55 s |
Is 31555 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 | No (remainder 1) | 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 (31555 ÷ 5 = 6311) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 1) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31555 a prime number?
No. 31555 = 5 × 6311, so it is divisible by 5.
What are the factors of 31555?
1, 5, 6311, 31555.
What is 31555 in binary?
111101101000011 (hexadecimal 7B43, octal 75503).
What is the square root of 31555?
About 177.6373.
Is 31555 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31555?
31555 is a semiprime: 5 × 6311, the product of two primes.