The number 124
124 is a composite number with 6 divisors. Its prime factorisation is × 31. Divisors (6): 1, 2, 4, 31, 62, 124.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
124 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
124 is composite. Its prime factorisation is
- 3
The divisors add up to 224; without 124 itself that is 100, so 124 is deficient (100 is less than 124). Euler's totient φ(124) = 60 numbers up to 124 share no factor with it.
- 4
The digits of 124 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 108 steps to reach 1.
LaTeX source of the formulas on this page
\[ 124 = 2^{2} \times 31 \]124 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 224 |
| Euler totient φ(n) | 60 |
| Square | 15376 |
| Cube | 1906624 |
| Square root | 11.135529 (= 2√31) |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 108 |
| Scientific notation | 1.24 × |
124 in other forms
| Form | Value |
|---|---|
| In words | one hundred and twenty-four |
| Roman numerals | CXXIV |
| Binary (base 2) | 1111100 |
| Octal (base 8) | 174 |
| Hexadecimal (base 16) | 7C |
| Base 3 | 11121 |
| As time | 124 seconds = 2 min 4 s |
Is 124 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (124 ÷ 2 = 62) | 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 | Yes (124 ÷ 4 = 31) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 124 a prime number?
No. 124 = × 31, so it is divisible by 2.
What are the factors of 124?
1, 2, 4, 31, 62, 124.
What is 124 in binary?
1111100 (hexadecimal 7C, octal 174).
What is the square root of 124?
About 11.1355, exactly 2√31.
What is 124 in Roman numerals?
CXXIV.
Is 124 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 124?
It is a composite number with 6 divisors.