The number 1399
1399 is the 222nd prime number. Its only divisors are 1 and 1399.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1399: the 222nd prime number.
- 2
1399 is prime, so its only factors are 1 and 1399. It is the 222nd prime; the next prime is 1409 and the one before is 1381.
- 3
The divisors add up to 1400; without 1399 itself that is 1, so 1399 is deficient (1 is less than 1399). Euler's totient φ(1399) = 1398 numbers up to 1399 share no factor with it.
- 4
The digits of 1399 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 65 steps to reach 1.
1399 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1400 |
| Euler totient φ(n) | 1398 |
| Square | 1957201 |
| Cube | 2738124199 |
| Square root | 37.403208 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 65 |
| Scientific notation | 1.399 × |
1399 in other forms
| Form | Value |
|---|---|
| In words | one thousand three hundred and ninety-nine |
| Roman numerals | MCCCXCIX |
| Binary (base 2) | 10101110111 |
| Octal (base 8) | 2567 |
| Hexadecimal (base 16) | 577 |
| Base 3 | 1220211 |
| As time | 1399 seconds = 23 min 19 s |
Is 1399 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 3) | 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 1) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1399 a prime number?
Yes. 1399 is divisible only by 1 and itself.
What are the factors of 1399?
1, 1399.
What is 1399 in binary?
10101110111 (hexadecimal 577, octal 2567).
What is the square root of 1399?
About 37.4032.
What is 1399 in Roman numerals?
MCCCXCIX.
Is 1399 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 1399?
1399 is the 222nd prime number.