The number 51121
51121 is a composite number with 8 divisors. Its prime factorisation is 7 × 67 × 109. Divisors (8): 1, 7, 67, 109, 469, 763, 7303, 51121.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 51121: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
51121 is composite. Its prime factorisation is
- 3
The divisors add up to 59840; without 51121 itself that is 8719, so 51121 is deficient (8719 is less than 51121). Euler's totient φ(51121) = 42768 numbers up to 51121 share no factor with it.
- 4
The digits of 51121 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 127 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51121 = 7 \times 67 \times 109 \]
51121 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 59840 |
| Euler totient φ(n) | 42768 |
| Square | 2613356641 |
| Cube | 133597404844561 |
| Square root | 226.099536 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 127 |
| Scientific notation | 5.1121 × |
51121 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand one hundred and twenty-one |
| Binary (base 2) | 1100011110110001 |
| Octal (base 8) | 143661 |
| Hexadecimal (base 16) | C7B1 |
| Base 3 | 2121010101 |
| As time | 51121 seconds = 14 h 12 min 1 s |
Is 51121 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 | Yes (51121 ÷ 7 = 7303) | 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 1) | 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 4) | 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 51121 a prime number?
No. 51121 = 7 × 67 × 109, so it is divisible by 7.
What are the factors of 51121?
1, 7, 67, 109, 469, 763, 7303, 51121.
What is 51121 in binary?
1100011110110001 (hexadecimal C7B1, octal 143661).
What is the square root of 51121?
About 226.0995.
Is 51121 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 51121?
51121 is a happy number: repeatedly adding the squares of its digits reaches 1.