The number 43121
43121 is a composite number with 8 divisors. Its prime factorisation is 13 × 31 × 107. Divisors (8): 1, 13, 31, 107, 403, 1391, 3317, 43121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 43121: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
43121 is composite. Its prime factorisation is
- 3
The divisors add up to 48384; without 43121 itself that is 5263, so 43121 is deficient (5263 is less than 43121). Euler's totient φ(43121) = 38160 numbers up to 43121 share no factor with it.
- 4
The digits of 43121 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 70 steps to reach 1.
LaTeX source of the formulas on this page
\[ 43121 = 13 \times 31 \times 107 \]
43121 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 48384 |
| Euler totient φ(n) | 38160 |
| Square | 1859420641 |
| Cube | 80180077460561 |
| Square root | 207.655965 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 70 |
| Scientific notation | 4.3121 × |
43121 in other forms
| Form | Value |
|---|---|
| In words | forty-three thousand one hundred and twenty-one |
| Binary (base 2) | 1010100001110001 |
| Octal (base 8) | 124161 |
| Hexadecimal (base 16) | A871 |
| Base 3 | 2012011002 |
| As time | 43121 seconds = 11 h 58 min 41 s |
Is 43121 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 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 1) | 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 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 43121 a prime number?
No. 43121 = 13 × 31 × 107, so it is divisible by 13.
What are the factors of 43121?
1, 13, 31, 107, 403, 1391, 3317, 43121.
What is 43121 in binary?
1010100001110001 (hexadecimal A871, octal 124161).
What is the square root of 43121?
About 207.6560.
Is 43121 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 43121?
43121 is a happy number: repeatedly adding the squares of its digits reaches 1.