The number 15400
15400 is a triangular number: 1 + 2 + … + 175 = 15400. Its prime factorisation is × × 7 × 11. Divisors (48): 1, 2, 4, 5, 7, 8, 10, 11, 14, 20, 22, 25, 28, 35, 40, 44 … 15400.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15400: a triangular number: 1 + 2 + … + 175 = 15400; a Harshad number: divisible by its digit sum 10.
- 2
15400 is composite. Its prime factorisation is
- 3
The divisors add up to 44640; without 15400 itself that is 29240, so 15400 is abundant (29240 is more than 15400). Euler's totient φ(15400) = 4800 numbers up to 15400 share no factor with it.
- 4
The digits of 15400 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15400 = 2^{3} \times 5^{2} \times 7 \times 11 \]15400 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 44640 |
| Euler totient φ(n) | 4800 |
| Square | 237160000 |
| Cube | 3652264000000 |
| Square root | 124.096736 (= 10√154) |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 53 |
| Scientific notation | 1.54 × |
15400 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand four hundred |
| Binary (base 2) | 11110000101000 |
| Octal (base 8) | 36050 |
| Hexadecimal (base 16) | 3C28 |
| Base 3 | 210010101 |
| As time | 15400 seconds = 4 h 16 min 40 s |
Is 15400 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15400 ÷ 2 = 7700) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (15400 ÷ 4 = 3850) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (15400 ÷ 5 = 3080) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (15400 ÷ 7 = 2200) | 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 (15400 ÷ 8 = 1925) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (15400 ÷ 10 = 1540) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (15400 ÷ 11 = 1400) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15400 a prime number?
No. 15400 = × × 7 × 11, so it is divisible by 2.
What are the factors of 15400?
1, 2, 4, 5, 7, 8, 10, 11, 14, 20, 22, 25, 28, 35, 40, 44, 50, 55, 56, 70, 77, 88, 100, 110, 140, 154, 175, 200, 220, 275, 280, 308, 350, 385, 440, 550, 616, 700, 770, 1100, 1400, 1540, 1925, 2200, 3080, 3850, 7700, 15400.
What is 15400 in binary?
11110000101000 (hexadecimal 3C28, octal 36050).
What is the square root of 15400?
About 124.0967, exactly 10√154.
Is 15400 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 15400?
15400 is a triangular number: 1 + 2 + … + 175 = 15400; a Harshad number: divisible by its digit sum 10.