The number 757
757 is a palindromic prime: it reads the same backwards and is prime, the 134th prime number and a palindrome: it reads 757 backwards too. Its only divisors are 1 and 757.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 757: a palindromic prime: it reads the same backwards and is prime; the 134th prime number; a palindrome: it reads 757 backwards too.
- 2
757 is prime, so its only factors are 1 and 757. It is the 134th prime; the next prime is 761 and the one before is 751.
- 3
The divisors add up to 758; without 757 itself that is 1, so 757 is deficient (1 is less than 757). Euler's totient φ(757) = 756 numbers up to 757 share no factor with it.
- 4
The digits of 757 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 108 steps to reach 1.
757 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 758 |
| Euler totient φ(n) | 756 |
| Square | 573049 |
| Cube | 433798093 |
| Square root | 27.513633 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 108 |
| Scientific notation | 7.57 × |
757 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and fifty-seven |
| Roman numerals | DCCLVII |
| Binary (base 2) | 1011110101 |
| Octal (base 8) | 1365 |
| Hexadecimal (base 16) | 2F5 |
| Base 3 | 1001001 |
| As time | 757 seconds = 12 min 37 s |
Is 757 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 2) | 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 1) | 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 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 757 a prime number?
Yes. 757 is divisible only by 1 and itself.
What are the factors of 757?
1, 757.
What is 757 in binary?
1011110101 (hexadecimal 2F5, octal 1365).
What is the square root of 757?
About 27.5136.
What is 757 in Roman numerals?
DCCLVII.
Is 757 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 757?
757 is a palindromic prime: it reads the same backwards and is prime; the 134th prime number; a palindrome: it reads 757 backwards too.