The number 7750
7750 is a triangular number: 1 + 2 + … + 124 = 7750. Its prime factorisation is 2 × × 31. Divisors (16): 1, 2, 5, 10, 25, 31, 50, 62, 125, 155, 250, 310, 775, 1550, 3875, 7750.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7750: a triangular number: 1 + 2 + … + 124 = 7750.
- 2
7750 is composite. Its prime factorisation is
- 3
The divisors add up to 14976; without 7750 itself that is 7226, so 7750 is deficient (7226 is less than 7750). Euler's totient φ(7750) = 3000 numbers up to 7750 share no factor with it.
- 4
The digits of 7750 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7750 = 2 \times 5^{3} \times 31 \]7750 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 14976 |
| Euler totient φ(n) | 3000 |
| Square | 60062500 |
| Cube | 465484375000 |
| Square root | 88.034084 (= 5√310) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 52 |
| Scientific notation | 7.75 × |
7750 in other forms
| Form | Value |
|---|---|
| In words | seven thousand seven hundred and fifty |
| Binary (base 2) | 1111001000110 |
| Octal (base 8) | 17106 |
| Hexadecimal (base 16) | 1E46 |
| Base 3 | 101122001 |
| As time | 7750 seconds = 2 h 9 min 10 s |
Is 7750 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7750 ÷ 2 = 3875) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (7750 ÷ 5 = 1550) | 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 1) | 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 6) | 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 | Yes (7750 ÷ 10 = 775) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7750 a prime number?
No. 7750 = 2 × × 31, so it is divisible by 2.
What are the factors of 7750?
1, 2, 5, 10, 25, 31, 50, 62, 125, 155, 250, 310, 775, 1550, 3875, 7750.
What is 7750 in binary?
1111001000110 (hexadecimal 1E46, octal 17106).
What is the square root of 7750?
About 88.0341, exactly 5√310.
Is 7750 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 7750?
7750 is a triangular number: 1 + 2 + … + 124 = 7750.