The number 87870
87870 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 5 × 29 × 101. Divisors (32): 1, 2, 3, 5, 6, 10, 15, 29, 30, 58, 87, 101, 145, 174, 202, 290 … 87870.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87870: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 30.
- 2
87870 is composite. Its prime factorisation is
- 3
The divisors add up to 220320; without 87870 itself that is 132450, so 87870 is abundant (132450 is more than 87870). Euler's totient φ(87870) = 22400 numbers up to 87870 share no factor with it.
- 4
The digits of 87870 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87870 = 2 \times 3 \times 5 \times 29 \times 101 \]
87870 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 220320 |
| Euler totient φ(n) | 22400 |
| Square | 7721136900 |
| Cube | 678456299403000 |
| Square root | 296.428744 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 58 |
| Scientific notation | 8.787 × |
87870 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand eight hundred and seventy |
| Binary (base 2) | 10101011100111110 |
| Octal (base 8) | 253476 |
| Hexadecimal (base 16) | 1573E |
| Base 3 | 11110112110 |
| As time | 87870 seconds = 24 h 24 min 30 s |
Is 87870 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87870 ÷ 2 = 43935) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (87870 ÷ 3 = 29290) | 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 (87870 ÷ 5 = 17574) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (87870 ÷ 6 = 14645) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (87870 ÷ 10 = 8787) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87870 a prime number?
No. 87870 = 2 × 3 × 5 × 29 × 101, so it is divisible by 2.
What are the factors of 87870?
1, 2, 3, 5, 6, 10, 15, 29, 30, 58, 87, 101, 145, 174, 202, 290, 303, 435, 505, 606, 870, 1010, 1515, 2929, 3030, 5858, 8787, 14645, 17574, 29290, 43935, 87870.
What is 87870 in binary?
10101011100111110 (hexadecimal 1573E, octal 253476).
What is the square root of 87870?
About 296.4287.
Is 87870 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 87870?
87870 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 30.