The number 29987
29987 is a composite number with 4 divisors. Its prime factorisation is 157 × 191. Divisors (4): 1, 157, 191, 29987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 29987: a semiprime: 157 × 191, the product of two primes.
- 2
29987 is composite. Its prime factorisation is
- 3
The divisors add up to 30336; without 29987 itself that is 349, so 29987 is deficient (349 is less than 29987). Euler's totient φ(29987) = 29640 numbers up to 29987 share no factor with it.
- 4
The digits of 29987 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 64 steps to reach 1.
LaTeX source of the formulas on this page
\[ 29987 = 157 \times 191 \]
29987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 30336 |
| Euler totient φ(n) | 29640 |
| Square | 899220169 |
| Cube | 26964915207803 |
| Square root | 173.167549 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 64 |
| Scientific notation | 2.9987 × |
29987 in other forms
| Form | Value |
|---|---|
| In words | twenty-nine thousand nine hundred and eighty-seven |
| Binary (base 2) | 111010100100011 |
| Octal (base 8) | 72443 |
| Hexadecimal (base 16) | 7523 |
| Base 3 | 1112010122 |
| As time | 29987 seconds = 8 h 19 min 47 s |
Is 29987 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 2) | 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 | 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 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 29987 a prime number?
No. 29987 = 157 × 191, so it is divisible by 157.
What are the factors of 29987?
1, 157, 191, 29987.
What is 29987 in binary?
111010100100011 (hexadecimal 7523, octal 72443).
What is the square root of 29987?
About 173.1675.
Is 29987 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 29987?
29987 is a semiprime: 157 × 191, the product of two primes.