The number 87401
87401 is a composite number with 4 divisors. Its prime factorisation is 71 × 1231. Divisors (4): 1, 71, 1231, 87401.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87401: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 71 × 1231, the product of two primes.
- 2
87401 is composite. Its prime factorisation is
- 3
The divisors add up to 88704; without 87401 itself that is 1303, so 87401 is deficient (1303 is less than 87401). Euler's totient φ(87401) = 86100 numbers up to 87401 share no factor with it.
- 4
The digits of 87401 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 58 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87401 = 71 \times 1231 \]
87401 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 88704 |
| Euler totient φ(n) | 86100 |
| Square | 7638934801 |
| Cube | 667650540542201 |
| Square root | 295.636601 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 58 |
| Scientific notation | 8.7401 × |
87401 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand four hundred and one |
| Binary (base 2) | 10101010101101001 |
| Octal (base 8) | 252551 |
| Hexadecimal (base 16) | 15569 |
| Base 3 | 11102220002 |
| As time | 87401 seconds = 24 h 16 min 41 s |
Is 87401 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87401 a prime number?
No. 87401 = 71 × 1231, so it is divisible by 71.
What are the factors of 87401?
1, 71, 1231, 87401.
What is 87401 in binary?
10101010101101001 (hexadecimal 15569, octal 252551).
What is the square root of 87401?
About 295.6366.
Is 87401 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 87401?
87401 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 71 × 1231, the product of two primes.