The number 66001
66001 is a composite number with 4 divisors. Its prime factorisation is 13 × 5077. Divisors (4): 1, 13, 5077, 66001.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 66001: a Harshad number: divisible by its digit sum 13; a semiprime: 13 × 5077, the product of two primes.
- 2
66001 is composite. Its prime factorisation is
- 3
The divisors add up to 71092; without 66001 itself that is 5091, so 66001 is deficient (5091 is less than 66001). Euler's totient φ(66001) = 60912 numbers up to 66001 share no factor with it.
- 4
The digits of 66001 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 68 steps to reach 1.
LaTeX source of the formulas on this page
\[ 66001 = 13 \times 5077 \]
66001 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 71092 |
| Euler totient φ(n) | 60912 |
| Square | 4356132001 |
| Cube | 287509068198001 |
| Square root | 256.906598 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 68 |
| Scientific notation | 6.6001 × |
66001 in other forms
| Form | Value |
|---|---|
| In words | sixty-six thousand and one |
| Binary (base 2) | 10000000111010001 |
| Octal (base 8) | 200721 |
| Hexadecimal (base 16) | 101D1 |
| Base 3 | 10100112111 |
| As time | 66001 seconds = 18 h 20 min 1 s |
Is 66001 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 1) | 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 5) | 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 1) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 66001 a prime number?
No. 66001 = 13 × 5077, so it is divisible by 13.
What are the factors of 66001?
1, 13, 5077, 66001.
What is 66001 in binary?
10000000111010001 (hexadecimal 101D1, octal 200721).
What is the square root of 66001?
About 256.9066.
Is 66001 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 66001?
66001 is a Harshad number: divisible by its digit sum 13; a semiprime: 13 × 5077, the product of two primes.