The number 29
29 is a twin prime (29 and 31 are both prime) and the 10th prime number. Its only divisors are 1 and 29.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 29: a twin prime (29 and 31 are both prime); the 10th prime number.
- 2
29 is prime, so its only factors are 1 and 29. It is the 10th prime; the next prime is 31 and the one before is 23.
- 3
The divisors add up to 30; without 29 itself that is 1, so 29 is deficient (1 is less than 29). Euler's totient φ(29) = 28 numbers up to 29 share no factor with it.
- 4
The digits of 29 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 18 steps to reach 1.
29 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 30 |
| Euler totient φ(n) | 28 |
| Square | 841 |
| Cube | 24389 |
| Square root | 5.385165 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 18 |
| Scientific notation | 2.9 × |
29 in other forms
| Form | Value |
|---|---|
| In words | twenty-nine |
| Roman numerals | XXIX |
| Binary (base 2) | 11101 |
| Octal (base 8) | 35 |
| Hexadecimal (base 16) | 1D |
| Base 3 | 1002 |
| As time | 29 seconds |
Is 29 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 1) | 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 5) | 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 9) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 29 a prime number?
Yes. 29 is divisible only by 1 and itself.
What are the factors of 29?
1, 29.
What is 29 in binary?
11101 (hexadecimal 1D, octal 35).
What is the square root of 29?
About 5.3852.
What is 29 in Roman numerals?
XXIX.
Is 29 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 29?
29 is a twin prime (29 and 31 are both prime); the 10th prime number.