The number 55121
55121 is a composite number with 4 divisors. Its prime factorisation is 11 × 5011. Divisors (4): 1, 11, 5011, 55121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 55121: a semiprime: 11 × 5011, the product of two primes.
- 2
55121 is composite. Its prime factorisation is
- 3
The divisors add up to 60144; without 55121 itself that is 5023, so 55121 is deficient (5023 is less than 55121). Euler's totient φ(55121) = 50100 numbers up to 55121 share no factor with it.
- 4
The digits of 55121 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 184 steps to reach 1.
LaTeX source of the formulas on this page
\[ 55121 = 11 \times 5011 \]
55121 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 60144 |
| Euler totient φ(n) | 50100 |
| Square | 3038324641 |
| Cube | 167475492536561 |
| Square root | 234.778619 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 184 |
| Scientific notation | 5.5121 × |
55121 in other forms
| Form | Value |
|---|---|
| In words | fifty-five thousand one hundred and twenty-one |
| Binary (base 2) | 1101011101010001 |
| Octal (base 8) | 153521 |
| Hexadecimal (base 16) | D751 |
| Base 3 | 2210121112 |
| As time | 55121 seconds = 15 h 18 min 41 s |
Is 55121 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 3) | 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 5) | 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 (55121 ÷ 11 = 5011) | 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 55121 a prime number?
No. 55121 = 11 × 5011, so it is divisible by 11.
What are the factors of 55121?
1, 11, 5011, 55121.
What is 55121 in binary?
1101011101010001 (hexadecimal D751, octal 153521).
What is the square root of 55121?
About 234.7786.
Is 55121 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 55121?
55121 is a semiprime: 11 × 5011, the product of two primes.