The number 78900
78900 is a composite number with 36 divisors. Its prime factorisation is × 3 × × 263. Divisors (36): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 25, 30, 50, 60, 75, 100 … 78900.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
78900 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
78900 is composite. Its prime factorisation is
- 3
The divisors add up to 229152; without 78900 itself that is 150252, so 78900 is abundant (150252 is more than 78900). Euler's totient φ(78900) = 20960 numbers up to 78900 share no factor with it.
- 4
The digits of 78900 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78900 = 2^{2} \times 3 \times 5^{2} \times 263 \]78900 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 229152 |
| Euler totient φ(n) | 20960 |
| Square | 6225210000 |
| Cube | 491169069000000 |
| Square root | 280.891438 (= 10√789) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 76 |
| Scientific notation | 7.89 × |
78900 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand nine hundred |
| Binary (base 2) | 10011010000110100 |
| Octal (base 8) | 232064 |
| Hexadecimal (base 16) | 13434 |
| Base 3 | 11000020020 |
| As time | 78900 seconds = 21 h 55 min 0 s |
Is 78900 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (78900 ÷ 2 = 39450) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (78900 ÷ 3 = 26300) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (78900 ÷ 4 = 19725) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (78900 ÷ 5 = 15780) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (78900 ÷ 6 = 13150) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (78900 ÷ 10 = 7890) | 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 | Yes (78900 ÷ 12 = 6575) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 78900 a prime number?
No. 78900 = × 3 × × 263, so it is divisible by 2.
What are the factors of 78900?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 25, 30, 50, 60, 75, 100, 150, 263, 300, 526, 789, 1052, 1315, 1578, 2630, 3156, 3945, 5260, 6575, 7890, 13150, 15780, 19725, 26300, 39450, 78900.
What is 78900 in binary?
10011010000110100 (hexadecimal 13434, octal 232064).
What is the square root of 78900?
About 280.8914, exactly 10√789.
Is 78900 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 78900?
It is a composite number with 36 divisors.