The number 1397
1397 is a binary palindrome (10101110101). Its prime factorisation is 11 × 127. Divisors (4): 1, 11, 127, 1397.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1397: a binary palindrome (10101110101); a semiprime: 11 × 127, the product of two primes.
- 2
1397 is composite. Its prime factorisation is
- 3
The divisors add up to 1536; without 1397 itself that is 139, so 1397 is deficient (139 is less than 1397). Euler's totient φ(1397) = 1260 numbers up to 1397 share no factor with it.
- 4
The digits of 1397 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 34 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1397 = 11 \times 127 \]
1397 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1536 |
| Euler totient φ(n) | 1260 |
| Square | 1951609 |
| Cube | 2726397773 |
| Square root | 37.376463 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 34 |
| Scientific notation | 1.397 × |
1397 in other forms
| Form | Value |
|---|---|
| In words | one thousand three hundred and ninety-seven |
| Roman numerals | MCCCXCVII |
| Binary (base 2) | 10101110101 |
| Octal (base 8) | 2565 |
| Hexadecimal (base 16) | 575 |
| Base 3 | 1220202 |
| As time | 1397 seconds = 23 min 17 s |
Is 1397 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 4) | 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 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (1397 ÷ 11 = 127) | 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 1397 a prime number?
No. 1397 = 11 × 127, so it is divisible by 11.
What are the factors of 1397?
1, 11, 127, 1397.
What is 1397 in binary?
10101110101 (hexadecimal 575, octal 2565).
What is the square root of 1397?
About 37.3765.
What is 1397 in Roman numerals?
MCCCXCVII.
Is 1397 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 1397?
1397 is a binary palindrome (10101110101); a semiprime: 11 × 127, the product of two primes.