The number 122
122 is a composite number with 4 divisors. Its prime factorisation is 2 × 61. Divisors (4): 1, 2, 61, 122.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 122: a semiprime: 2 × 61, the product of two primes.
- 2
122 is composite. Its prime factorisation is
- 3
The divisors add up to 186; without 122 itself that is 64, so 122 is deficient (64 is less than 122). Euler's totient φ(122) = 60 numbers up to 122 share no factor with it.
- 4
The digits of 122 add up to 5, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 20 steps to reach 1.
LaTeX source of the formulas on this page
\[ 122 = 2 \times 61 \]
122 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 186 |
| Euler totient φ(n) | 60 |
| Square | 14884 |
| Cube | 1815848 |
| Square root | 11.045361 |
| Digit sum / digital root | 5 / 5 |
| Collatz steps to 1 | 20 |
| Scientific notation | 1.22 × |
122 in other forms
| Form | Value |
|---|---|
| In words | one hundred and twenty-two |
| Roman numerals | CXXII |
| Binary (base 2) | 1111010 |
| Octal (base 8) | 172 |
| Hexadecimal (base 16) | 7A |
| Base 3 | 11112 |
| As time | 122 seconds = 2 min 2 s |
Is 122 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (122 ÷ 2 = 61) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 2) | 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 2) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 122 a prime number?
No. 122 = 2 × 61, so it is divisible by 2.
What are the factors of 122?
1, 2, 61, 122.
What is 122 in binary?
1111010 (hexadecimal 7A, octal 172).
What is the square root of 122?
About 11.0454.
What is 122 in Roman numerals?
CXXII.
Is 122 divisible by 3?
No. Its digits add up to 5, which is not a multiple of 3.
What is special about the number 122?
122 is a semiprime: 2 × 61, the product of two primes.