The number 71980
71980 is a composite number with 24 divisors. Its prime factorisation is × 5 × 59 × 61. Divisors (24): 1, 2, 4, 5, 10, 20, 59, 61, 118, 122, 236, 244, 295, 305, 590, 610 … 71980.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
71980 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
71980 is composite. Its prime factorisation is
- 3
The divisors add up to 156240; without 71980 itself that is 84260, so 71980 is abundant (84260 is more than 71980). Euler's totient φ(71980) = 27840 numbers up to 71980 share no factor with it.
- 4
The digits of 71980 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71980 = 2^{2} \times 5 \times 59 \times 61 \]71980 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 156240 |
| Euler totient φ(n) | 27840 |
| Square | 5181120400 |
| Cube | 372937046392000 |
| Square root | 268.290887 (= 2√17995) |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.198 × |
71980 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand nine hundred and eighty |
| Binary (base 2) | 10001100100101100 |
| Octal (base 8) | 214454 |
| Hexadecimal (base 16) | 1192C |
| Base 3 | 10122201221 |
| As time | 71980 seconds = 19 h 59 min 40 s |
Is 71980 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71980 ÷ 2 = 35990) | 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 (71980 ÷ 4 = 17995) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (71980 ÷ 5 = 14396) | 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 6) | 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 | Yes (71980 ÷ 10 = 7198) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 71980 a prime number?
No. 71980 = × 5 × 59 × 61, so it is divisible by 2.
What are the factors of 71980?
1, 2, 4, 5, 10, 20, 59, 61, 118, 122, 236, 244, 295, 305, 590, 610, 1180, 1220, 3599, 7198, 14396, 17995, 35990, 71980.
What is 71980 in binary?
10001100100101100 (hexadecimal 1192C, octal 214454).
What is the square root of 71980?
About 268.2909, exactly 2√17995.
Is 71980 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 71980?
It is a composite number with 24 divisors.