The number 74747
74747 is a palindromic prime: it reads the same backwards and is prime, the 7371st prime number and a palindrome: it reads 74747 backwards too. Its only divisors are 1 and 74747.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 74747: a palindromic prime: it reads the same backwards and is prime; the 7371st prime number; a palindrome: it reads 74747 backwards too.
- 2
74747 is prime, so its only factors are 1 and 74747. It is the 7371st prime; the next prime is 74759 and the one before is 74731.
- 3
The divisors add up to 74748; without 74747 itself that is 1, so 74747 is deficient (1 is less than 74747). Euler's totient φ(74747) = 74746 numbers up to 74747 share no factor with it.
- 4
The digits of 74747 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 187 steps to reach 1.
74747 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 74748 |
| Euler totient φ(n) | 74746 |
| Square | 5587114009 |
| Cube | 417620010830723 |
| Square root | 273.398976 |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.4747 × |
74747 in other forms
| Form | Value |
|---|---|
| In words | seventy-four thousand seven hundred and forty-seven |
| Binary (base 2) | 10010001111111011 |
| Octal (base 8) | 221773 |
| Hexadecimal (base 16) | 123FB |
| Base 3 | 10210112102 |
| As time | 74747 seconds = 20 h 45 min 47 s |
Is 74747 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 3) | 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 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 3) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 74747 a prime number?
Yes. 74747 is divisible only by 1 and itself.
What are the factors of 74747?
1, 74747.
What is 74747 in binary?
10010001111111011 (hexadecimal 123FB, octal 221773).
What is the square root of 74747?
About 273.3990.
Is 74747 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 74747?
74747 is a palindromic prime: it reads the same backwards and is prime; the 7371st prime number; a palindrome: it reads 74747 backwards too.