The number 7225

No. 7225 = 5^2 × 17^2, so it is divisible by 5.

7225 is a perfect square (85²). Its prime factorisation is $5^{2}$ × $17^{2}$ . Divisors (9): 1, 5, 17, 25, 85, 289, 425, 1445, 7225.

Number

Pick any whole number from 1 to 100,000.

7225 = 5^{2} \times 17^{2}

How to work it out

1
What is special about 7225: a perfect square (85²); a happy number: repeatedly adding the squares of its digits reaches 1.
2
7225 is composite. Its prime factorisation is
$7225 = 5^{2} \times 17^{2}$
3
The divisors add up to 9517; without 7225 itself that is 2292, so 7225 is deficient (2292 is less than 7225). Euler's totient φ(7225) = 5440 numbers up to 7225 share no factor with it.
4
The digits of 7225 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.

LaTeX source of the formulas on this page

\[ 7225 = 5^{2} \times 17^{2} \]

Form	Value
In words	seven thousand two hundred and twenty-five
Binary (base 2)	1110000111001
Octal (base 8)	16071
Hexadecimal (base 16)	1C39
Base 3	100220121
As time	7225 seconds = 2 h 0 min 25 s

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 1)	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	Yes (7225 ÷ 5 = 1445)	A number is divisible by 5 if the last digit is 0 or 5.
6	No (remainder 1)	A number is divisible by 6 if it is divisible by both 2 and 3.
7	No (remainder 1)	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 7)	A number is divisible by 9 if the digits add up to a multiple of 9.
10	No (remainder 5)	A number is divisible by 10 if the last digit is 0.
11	No (remainder 9)	A number is divisible by 11 if the alternating sum of the digits is a multiple of 11.
12	No (remainder 1)	A number is divisible by 12 if it is divisible by both 3 and 4.

Is 7225 a prime number?

No. 7225 = $5^{2}$ × $17^{2}$ , so it is divisible by 5.

What are the factors of 7225?

1, 5, 17, 25, 85, 289, 425, 1445, 7225.

What is 7225 in binary?

1110000111001 (hexadecimal 1C39, octal 16071).

What is the square root of 7225?

85, because 85 × 85 = 7225.

Is 7225 divisible by 3?

No. Its digits add up to 16, which is not a multiple of 3.

What is special about the number 7225?

7225 is a perfect square (85²); a happy number: repeatedly adding the squares of its digits reaches 1.