The number 87402
87402 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 7 × 2081. Divisors (16): 1, 2, 3, 6, 7, 14, 21, 42, 2081, 4162, 6243, 12486, 14567, 29134, 43701, 87402.
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How to work it out
- 1
What is special about 87402: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 21.
- 2
87402 is composite. Its prime factorisation is
- 3
The divisors add up to 199872; without 87402 itself that is 112470, so 87402 is abundant (112470 is more than 87402). Euler's totient φ(87402) = 24960 numbers up to 87402 share no factor with it.
- 4
The digits of 87402 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 120 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87402 = 2 \times 3 \times 7 \times 2081 \]
87402 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 199872 |
| Euler totient φ(n) | 24960 |
| Square | 7639109604 |
| Cube | 667673457608808 |
| Square root | 295.638293 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 120 |
| Scientific notation | 8.7402 × |
87402 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand four hundred and two |
| Binary (base 2) | 10101010101101010 |
| Octal (base 8) | 252552 |
| Hexadecimal (base 16) | 1556A |
| Base 3 | 11102220010 |
| As time | 87402 seconds = 24 h 16 min 42 s |
Is 87402 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87402 ÷ 2 = 43701) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (87402 ÷ 3 = 29134) | 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 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (87402 ÷ 6 = 14567) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (87402 ÷ 7 = 12486) | 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 2) | 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 | No (remainder 2) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87402 a prime number?
No. 87402 = 2 × 3 × 7 × 2081, so it is divisible by 2.
What are the factors of 87402?
1, 2, 3, 6, 7, 14, 21, 42, 2081, 4162, 6243, 12486, 14567, 29134, 43701, 87402.
What is 87402 in binary?
10101010101101010 (hexadecimal 1556A, octal 252552).
What is the square root of 87402?
About 295.6383.
Is 87402 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 87402?
87402 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 21.