Is 485 a prime number?

It is possible to find out using mathematical methods whether a given integer is a prime number or not.

For 485, the answer is: No, 485 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 485) is as follows: 1, 5, 97, 485.

For 485 to be a prime number, it would have been required that 485 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

Actually, one can immediately see that 485 cannot be prime, because 5 is one of its divisors: indeed, a number ending with 0 or 5 has necessarily 5 among its divisors. The last digit of 485 is 5, so it is divisible by 5 and is therefore not prime.

As a consequence:

485 is a multiple of 1
485 is a multiple of 5
485 is a multiple of 97

For 485 to be a prime number, it would have been required that 485 has only two divisors, i.e., itself and 1.

However, 485 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 485 = 5 x 97, where 5 and 97 are both prime numbers.

Is 485 a deficient number?

Yes, 485 is a deficient number, that is to say 485 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 485 without 485 itself (that is 1 + 5 + 97 = 103).

Parity of 485

485 is an odd number, because it is not evenly divisible by 2.

Find out more:

What is an even number?

Is 485 a perfect square number?

A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 485 is about 22.023.

Thus, the square root of 485 is not an integer, and therefore 485 is not a square number.

What is the square number of 485?

The square of a number (here 485) is the result of the product of this number (485) by itself (i.e., 485 × 485); the square of 485 is sometimes called "raising 485 to the power 2", or "485 squared".

The square of 485 is 235 225 because 485 × 485 = 485² = 235 225.

As a consequence, 485 is the square root of 235 225.

Number of digits of 485

485 is a number with 3 digits.

What are the multiples of 485?

The multiples of 485 are all integers evenly divisible by 485, that is all numbers such that the remainder of the division by 485 is zero. There are infinitely many multiples of 485. The smallest multiples of 485 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 485 too, since 0 × 485 = 0
485: indeed, 485 is a multiple of itself, since 485 is evenly divisible by 485 (we have 485 / 485 = 1, so the remainder of this division is indeed zero)
970: indeed, 970 = 485 × 2
1 455: indeed, 1 455 = 485 × 3
1 940: indeed, 1 940 = 485 × 4
2 425: indeed, 2 425 = 485 × 5
etc.

How to determine whether an integer is a prime number?

To determine the primality of a number, several algorithms can be used. The most naive technique is to test all divisors strictly smaller to the number of which we want to determine the primality (here 485). First, we can eliminate all even numbers greater than 2 (and hence 4, 6, 8…). Then, we can stop this check when we reach the square root of the number of which we want to determine the primality (here the square root is about 22.023). Historically, the sieve of Eratosthenes (dating from the Greek mathematics) implements this technique in a relatively efficient manner.

More modern techniques include the sieve of Atkin, probabilistic algorithms, and the cyclotomic AKS test.

Numbers near 485

Preceding numbers: …483, 484
Following numbers: 486, 487…

Nearest numbers from 485

Preceding prime number: 479
Following prime number: 487