The number 12421
12421 is a palindromic prime: it reads the same backwards and is prime, the 1483rd prime number and a palindrome: it reads 12421 backwards too. Its only divisors are 1 and 12421.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 12421: a palindromic prime: it reads the same backwards and is prime; the 1483rd prime number; a palindrome: it reads 12421 backwards too.
- 2
12421 is prime, so its only factors are 1 and 12421. It is the 1483rd prime; the next prime is 12433 and the one before is 12413.
- 3
The divisors add up to 12422; without 12421 itself that is 1, so 12421 is deficient (1 is less than 12421). Euler's totient φ(12421) = 12420 numbers up to 12421 share no factor with it.
- 4
The digits of 12421 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 156 steps to reach 1.
12421 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 12422 |
| Euler totient φ(n) | 12420 |
| Square | 154281241 |
| Cube | 1916327294461 |
| Square root | 111.449540 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 156 |
| Scientific notation | 1.2421 × |
12421 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand four hundred and twenty-one |
| Binary (base 2) | 11000010000101 |
| Octal (base 8) | 30205 |
| Hexadecimal (base 16) | 3085 |
| Base 3 | 122001001 |
| As time | 12421 seconds = 3 h 27 min 1 s |
Is 12421 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 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 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 5) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 12421 a prime number?
Yes. 12421 is divisible only by 1 and itself.
What are the factors of 12421?
1, 12421.
What is 12421 in binary?
11000010000101 (hexadecimal 3085, octal 30205).
What is the square root of 12421?
About 111.4495.
Is 12421 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 12421?
12421 is a palindromic prime: it reads the same backwards and is prime; the 1483rd prime number; a palindrome: it reads 12421 backwards too.