The number 667
667 is a composite number with 4 divisors. Its prime factorisation is 23 × 29. Divisors (4): 1, 23, 29, 667.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 667: a semiprime: 23 × 29, the product of two primes.
- 2
667 is composite. Its prime factorisation is
- 3
The divisors add up to 720; without 667 itself that is 53, so 667 is deficient (53 is less than 667). Euler's totient φ(667) = 616 numbers up to 667 share no factor with it.
- 4
The digits of 667 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 144 steps to reach 1.
LaTeX source of the formulas on this page
\[ 667 = 23 \times 29 \]
667 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 720 |
| Euler totient φ(n) | 616 |
| Square | 444889 |
| Cube | 296740963 |
| Square root | 25.826343 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 144 |
| Scientific notation | 6.67 × |
667 in other forms
| Form | Value |
|---|---|
| In words | six hundred and sixty-seven |
| Roman numerals | DCLXVII |
| Binary (base 2) | 1010011011 |
| Octal (base 8) | 1233 |
| Hexadecimal (base 16) | 29B |
| Base 3 | 220201 |
| As time | 667 seconds = 11 min 7 s |
Is 667 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 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 2) | 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 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 7) | 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 667 a prime number?
No. 667 = 23 × 29, so it is divisible by 23.
What are the factors of 667?
1, 23, 29, 667.
What is 667 in binary?
1010011011 (hexadecimal 29B, octal 1233).
What is the square root of 667?
About 25.8263.
What is 667 in Roman numerals?
DCLXVII.
Is 667 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 667?
667 is a semiprime: 23 × 29, the product of two primes.