The number 21377
21377 is a twin prime (21377 and 21379 are both prime) and the 2398th prime number. Its only divisors are 1 and 21377.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21377: a twin prime (21377 and 21379 are both prime); the 2398th prime number.
- 2
21377 is prime, so its only factors are 1 and 21377. It is the 2398th prime; the next prime is 21379 and the one before is 21347.
- 3
The divisors add up to 21378; without 21377 itself that is 1, so 21377 is deficient (1 is less than 21377). Euler's totient φ(21377) = 21376 numbers up to 21377 share no factor with it.
- 4
The digits of 21377 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
21377 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 21378 |
| Euler totient φ(n) | 21376 |
| Square | 456976129 |
| Cube | 9768778709633 |
| Square root | 146.208755 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 48 |
| Scientific notation | 2.1377 × |
21377 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and seventy-seven |
| Binary (base 2) | 101001110000001 |
| Octal (base 8) | 51601 |
| Hexadecimal (base 16) | 5381 |
| Base 3 | 1002022202 |
| As time | 21377 seconds = 5 h 56 min 17 s |
Is 21377 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 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 1) | 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 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 21377 a prime number?
Yes. 21377 is divisible only by 1 and itself.
What are the factors of 21377?
1, 21377.
What is 21377 in binary?
101001110000001 (hexadecimal 5381, octal 51601).
What is the square root of 21377?
About 146.2088.
Is 21377 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 21377?
21377 is a twin prime (21377 and 21379 are both prime); the 2398th prime number.