What is a irregular prime?

From Encyclopedia of Mathematics. An odd prime number p for which the number of classes of ideals in the cyclotomic field Q(e2πi/p) is divisible by p. All other odd prime numbers are called regular.

What is the simple definition of prime numbers?

Definition of prime number : any integer other than 0 or ± 1 that is not divisible without remainder by any other integers except ± 1 and ± the integer itself.

Why is 17 not a prime number?

The number 17 is divisible only by 1 and the number itself. For a number to be classified as a prime number, it should have exactly two factors. Since 17 has exactly two factors, i.e. 1 and 17, it is a prime number.

What is a prime number for kids?

A prime number is a number greater than 1 with only two factors – themselves and 1. A prime number cannot be divided by any other numbers without leaving a remainder. An example of a prime number is 13.

How do you teach prime numbers?

To work out if a number is prime, you can try to divide the number by all numbers that are smaller than it. If it can only be evenly divided by 1 and the number itself, then it is a prime number. To look at a simple example, let’s try to work out if the number 7 is a prime number.

Is 11 a prime number Yes or no?

The first five prime numbers: 2, 3, 5, 7 and 11. A prime number is an integer, or whole number, that has only two factors — 1 and itself. Put another way, a prime number can be divided evenly only by 1 and by itself.

Is 33 a prime number Why?

No, 33 is not a prime number. The number 33 is divisible by 1, 3, 11, 33. Since 33 has more than two factors, i.e. 1, 3, 11, 33, it is not a prime number.

How do you teach students prime numbers?

1) Write out the numbers from 1 to 100 in ten rows of 10. 2) Cross off number 1, because all primes are greater than 1. 3) Number 2 is a prime, so we can keep it, but we need to cross off the multiples of 2 (i.e. even numbers). 4) Number 3 is also a prime, so again we keep it and cross off the multiples of 3.