The number 13421
13421 is the 1592nd prime number. Its only divisors are 1 and 13421.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13421: the 1592nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
13421 is prime, so its only factors are 1 and 13421. It is the 1592nd prime; the next prime is 13441 and the one before is 13417.
- 3
The divisors add up to 13422; without 13421 itself that is 1, so 13421 is deficient (1 is less than 13421). Euler's totient φ(13421) = 13420 numbers up to 13421 share no factor with it.
- 4
The digits of 13421 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 94 steps to reach 1.
13421 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 13422 |
| Euler totient φ(n) | 13420 |
| Square | 180123241 |
| Cube | 2417434017461 |
| Square root | 115.849040 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 94 |
| Scientific notation | 1.3421 × |
13421 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand four hundred and twenty-one |
| Binary (base 2) | 11010001101101 |
| Octal (base 8) | 32155 |
| Hexadecimal (base 16) | 346D |
| Base 3 | 200102002 |
| As time | 13421 seconds = 3 h 43 min 41 s |
Is 13421 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 2) | 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 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 13421 a prime number?
Yes. 13421 is divisible only by 1 and itself.
What are the factors of 13421?
1, 13421.
What is 13421 in binary?
11010001101101 (hexadecimal 346D, octal 32155).
What is the square root of 13421?
About 115.8490.
Is 13421 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 13421?
13421 is the 1592nd prime number; a happy number: repeatedly adding the squares of its digits reaches 1.