The number 29921
29921 is the 3240th prime number. Its only divisors are 1 and 29921.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 29921: the 3240th prime number.
- 2
29921 is prime, so its only factors are 1 and 29921. It is the 3240th prime; the next prime is 29927 and the one before is 29917.
- 3
The divisors add up to 29922; without 29921 itself that is 1, so 29921 is deficient (1 is less than 29921). Euler's totient φ(29921) = 29920 numbers up to 29921 share no factor with it.
- 4
The digits of 29921 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
29921 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 29922 |
| Euler totient φ(n) | 29920 |
| Square | 895266241 |
| Cube | 26787261196961 |
| Square root | 172.976877 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 116 |
| Scientific notation | 2.9921 × |
29921 in other forms
| Form | Value |
|---|---|
| In words | twenty-nine thousand nine hundred and twenty-one |
| Binary (base 2) | 111010011100001 |
| Octal (base 8) | 72341 |
| Hexadecimal (base 16) | 74E1 |
| Base 3 | 1112001012 |
| As time | 29921 seconds = 8 h 18 min 41 s |
Is 29921 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 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 | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 1) | 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 29921 a prime number?
Yes. 29921 is divisible only by 1 and itself.
What are the factors of 29921?
1, 29921.
What is 29921 in binary?
111010011100001 (hexadecimal 74E1, octal 72341).
What is the square root of 29921?
About 172.9769.
Is 29921 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 29921?
29921 is the 3240th prime number.