The number 31400
31400 is a composite number with 24 divisors. Its prime factorisation is × × 157. Divisors (24): 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 157, 200, 314, 628, 785 … 31400.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31400: a Harshad number: divisible by its digit sum 8.
- 2
31400 is composite. Its prime factorisation is
- 3
The divisors add up to 73470; without 31400 itself that is 42070, so 31400 is abundant (42070 is more than 31400). Euler's totient φ(31400) = 12480 numbers up to 31400 share no factor with it.
- 4
The digits of 31400 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 28 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31400 = 2^{3} \times 5^{2} \times 157 \]31400 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 73470 |
| Euler totient φ(n) | 12480 |
| Square | 985960000 |
| Cube | 30959144000000 |
| Square root | 177.200451 (= 10√314) |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 28 |
| Scientific notation | 3.14 × |
31400 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand four hundred |
| Binary (base 2) | 111101010101000 |
| Octal (base 8) | 75250 |
| Hexadecimal (base 16) | 7AA8 |
| Base 3 | 1121001222 |
| As time | 31400 seconds = 8 h 43 min 20 s |
Is 31400 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31400 ÷ 2 = 15700) | 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 | Yes (31400 ÷ 4 = 7850) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31400 ÷ 5 = 6280) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 | Yes (31400 ÷ 8 = 3925) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (31400 ÷ 10 = 3140) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31400 a prime number?
No. 31400 = × × 157, so it is divisible by 2.
What are the factors of 31400?
1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 157, 200, 314, 628, 785, 1256, 1570, 3140, 3925, 6280, 7850, 15700, 31400.
What is 31400 in binary?
111101010101000 (hexadecimal 7AA8, octal 75250).
What is the square root of 31400?
About 177.2005, exactly 10√314.
Is 31400 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 31400?
31400 is a Harshad number: divisible by its digit sum 8.