The number 1591
1591 is a composite number with 4 divisors. Its prime factorisation is 37 × 43. Divisors (4): 1, 37, 43, 1591.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1591: a semiprime: 37 × 43, the product of two primes.
- 2
1591 is composite. Its prime factorisation is
- 3
The divisors add up to 1672; without 1591 itself that is 81, so 1591 is deficient (81 is less than 1591). Euler's totient φ(1591) = 1512 numbers up to 1591 share no factor with it.
- 4
The digits of 1591 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 104 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1591 = 37 \times 43 \]
1591 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1672 |
| Euler totient φ(n) | 1512 |
| Square | 2531281 |
| Cube | 4027268071 |
| Square root | 39.887341 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 104 |
| Scientific notation | 1.591 × |
1591 in other forms
| Form | Value |
|---|---|
| In words | one thousand five hundred and ninety-one |
| Roman numerals | MDXCI |
| Binary (base 2) | 11000110111 |
| Octal (base 8) | 3067 |
| Hexadecimal (base 16) | 637 |
| Base 3 | 2011221 |
| As time | 1591 seconds = 26 min 31 s |
Is 1591 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 | No (remainder 1) | 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 2) | 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 7) | 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 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 1591 a prime number?
No. 1591 = 37 × 43, so it is divisible by 37.
What are the factors of 1591?
1, 37, 43, 1591.
What is 1591 in binary?
11000110111 (hexadecimal 637, octal 3067).
What is the square root of 1591?
About 39.8873.
What is 1591 in Roman numerals?
MDXCI.
Is 1591 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 1591?
1591 is a semiprime: 37 × 43, the product of two primes.