Is 427 a prime number?

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

For 427, the answer is: No, 427 is not a prime number.

The list of all positive divisors (i.e., the list of all integers that divide 427) is as follows: 1, 7, 61, 427.

For 427 to be a prime number, it would have been required that 427 has only two divisors, i.e., itself and 1.

Find out more:

What is a prime number?

As a consequence:

427 is a multiple of 1
427 is a multiple of 7
427 is a multiple of 61

For 427 to be a prime number, it would have been required that 427 has only two divisors, i.e., itself and 1.

However, 427 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 427 = 7 x 61, where 7 and 61 are both prime numbers.

Is 427 a deficient number?

Yes, 427 is a deficient number, that is to say 427 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 427 without 427 itself (that is 1 + 7 + 61 = 69).

Parity of 427

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

Find out more:

What is an even number?

Is 427 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 427 is about 20.664.

Thus, the square root of 427 is not an integer, and therefore 427 is not a square number.

What is the square number of 427?

The square of a number (here 427) is the result of the product of this number (427) by itself (i.e., 427 × 427); the square of 427 is sometimes called "raising 427 to the power 2", or "427 squared".

The square of 427 is 182 329 because 427 × 427 = 427² = 182 329.

As a consequence, 427 is the square root of 182 329.

Number of digits of 427

427 is a number with 3 digits.

What are the multiples of 427?

The multiples of 427 are all integers evenly divisible by 427, that is all numbers such that the remainder of the division by 427 is zero. There are infinitely many multiples of 427. The smallest multiples of 427 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 427 too, since 0 × 427 = 0
427: indeed, 427 is a multiple of itself, since 427 is evenly divisible by 427 (we have 427 / 427 = 1, so the remainder of this division is indeed zero)
854: indeed, 854 = 427 × 2
1 281: indeed, 1 281 = 427 × 3
1 708: indeed, 1 708 = 427 × 4
2 135: indeed, 2 135 = 427 × 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 427). 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 20.664). 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 427

Preceding numbers: …425, 426
Following numbers: 428, 429…

Nearest numbers from 427

Preceding prime number: 421
Following prime number: 431