The number 71621
71621 is a composite number with 8 divisors. Its prime factorisation is 11 × 17 × 383. Divisors (8): 1, 11, 17, 187, 383, 4213, 6511, 71621.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71621: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 17.
- 2
71621 is composite. Its prime factorisation is
- 3
The divisors add up to 82944; without 71621 itself that is 11323, so 71621 is deficient (11323 is less than 71621). Euler's totient φ(71621) = 61120 numbers up to 71621 share no factor with it.
- 4
The digits of 71621 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71621 = 11 \times 17 \times 383 \]
71621 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 82944 |
| Euler totient φ(n) | 61120 |
| Square | 5129567641 |
| Cube | 367384764016061 |
| Square root | 267.621001 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 94 |
| Scientific notation | 7.1621 × |
71621 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand six hundred and twenty-one |
| Binary (base 2) | 10001011111000101 |
| Octal (base 8) | 213705 |
| Hexadecimal (base 16) | 117C5 |
| Base 3 | 10122020122 |
| As time | 71621 seconds = 19 h 53 min 41 s |
Is 71621 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 1) | 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 8) | 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 | Yes (71621 ÷ 11 = 6511) | 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 71621 a prime number?
No. 71621 = 11 × 17 × 383, so it is divisible by 11.
What are the factors of 71621?
1, 11, 17, 187, 383, 4213, 6511, 71621.
What is 71621 in binary?
10001011111000101 (hexadecimal 117C5, octal 213705).
What is the square root of 71621?
About 267.6210.
Is 71621 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 71621?
71621 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 17.