The number 36991
36991 is a composite number with 4 divisors. Its prime factorisation is 71 × 521. Divisors (4): 1, 71, 521, 36991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 36991: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 71 × 521, the product of two primes.
- 2
36991 is composite. Its prime factorisation is
- 3
The divisors add up to 37584; without 36991 itself that is 593, so 36991 is deficient (593 is less than 36991). Euler's totient φ(36991) = 36400 numbers up to 36991 share no factor with it.
- 4
The digits of 36991 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 186 steps to reach 1.
LaTeX source of the formulas on this page
\[ 36991 = 71 \times 521 \]
36991 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 37584 |
| Euler totient φ(n) | 36400 |
| Square | 1368334081 |
| Cube | 50616045990271 |
| Square root | 192.330445 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 186 |
| Scientific notation | 3.6991 × |
36991 in other forms
| Form | Value |
|---|---|
| In words | thirty-six thousand nine hundred and ninety-one |
| Binary (base 2) | 1001000001111111 |
| Octal (base 8) | 110177 |
| Hexadecimal (base 16) | 907F |
| Base 3 | 1212202001 |
| As time | 36991 seconds = 10 h 16 min 31 s |
Is 36991 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 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 7) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 36991 a prime number?
No. 36991 = 71 × 521, so it is divisible by 71.
What are the factors of 36991?
1, 71, 521, 36991.
What is 36991 in binary?
1001000001111111 (hexadecimal 907F, octal 110177).
What is the square root of 36991?
About 192.3304.
Is 36991 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 36991?
36991 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 71 × 521, the product of two primes.