The number 1631
1631 is a composite number with 4 divisors. Its prime factorisation is 7 × 233. Divisors (4): 1, 7, 233, 1631.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1631: a semiprime: 7 × 233, the product of two primes.
- 2
1631 is composite. Its prime factorisation is
- 3
The divisors add up to 1872; without 1631 itself that is 241, so 1631 is deficient (241 is less than 1631). Euler's totient φ(1631) = 1392 numbers up to 1631 share no factor with it.
- 4
The digits of 1631 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 135 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1631 = 7 \times 233 \]
1631 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1872 |
| Euler totient φ(n) | 1392 |
| Square | 2660161 |
| Cube | 4338722591 |
| Square root | 40.385641 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 135 |
| Scientific notation | 1.631 × |
1631 in other forms
| Form | Value |
|---|---|
| In words | one thousand six hundred and thirty-one |
| Roman numerals | MDCXXXI |
| Binary (base 2) | 11001011111 |
| Octal (base 8) | 3137 |
| Hexadecimal (base 16) | 65F |
| Base 3 | 2020102 |
| As time | 1631 seconds = 27 min 11 s |
Is 1631 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 2) | 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 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (1631 ÷ 7 = 233) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1631 a prime number?
No. 1631 = 7 × 233, so it is divisible by 7.
What are the factors of 1631?
1, 7, 233, 1631.
What is 1631 in binary?
11001011111 (hexadecimal 65F, octal 3137).
What is the square root of 1631?
About 40.3856.
What is 1631 in Roman numerals?
MDCXXXI.
Is 1631 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 1631?
1631 is a semiprime: 7 × 233, the product of two primes.