The number 140
140 is a composite number with 12 divisors. Its prime factorisation is × 5 × 7. Divisors (12): 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 140: a Harshad number: divisible by its digit sum 5.
- 2
140 is composite. Its prime factorisation is
- 3
The divisors add up to 336; without 140 itself that is 196, so 140 is abundant (196 is more than 140). Euler's totient φ(140) = 48 numbers up to 140 share no factor with it.
- 4
The digits of 140 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 15 steps to reach 1.
LaTeX source of the formulas on this page
\[ 140 = 2^{2} \times 5 \times 7 \]140 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 336 |
| Euler totient φ(n) | 48 |
| Square | 19600 |
| Cube | 2744000 |
| Square root | 11.832160 (= 2√35) |
| Digit sum / digital root | 5 / 5 |
| Collatz steps to 1 | 15 |
| Scientific notation | 1.4 × |
140 in other forms
| Form | Value |
|---|---|
| In words | one hundred and forty |
| Roman numerals | CXL |
| Binary (base 2) | 10001100 |
| Octal (base 8) | 214 |
| Hexadecimal (base 16) | 8C |
| Base 3 | 12012 |
| As time | 140 seconds = 2 min 20 s |
Is 140 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (140 ÷ 2 = 70) | 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 | Yes (140 ÷ 4 = 35) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (140 ÷ 5 = 28) | 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 | Yes (140 ÷ 7 = 20) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (140 ÷ 10 = 14) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 140 a prime number?
No. 140 = × 5 × 7, so it is divisible by 2.
What are the factors of 140?
1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140.
What is 140 in binary?
10001100 (hexadecimal 8C, octal 214).
What is the square root of 140?
About 11.8322, exactly 2√35.
What is 140 in Roman numerals?
CXL.
Is 140 divisible by 3?
No. Its digits add up to 5, which is not a multiple of 3.
What is special about the number 140?
140 is a Harshad number: divisible by its digit sum 5.