# isPrime > Test if a value is a prime number.
A **prime number** is defined as an integer value greater than `1` which is only divisible by `1` and itself.
## Usage ```javascript var isPrime = require( '@stdlib/assert/is-prime' ); ``` #### isPrime( value ) Tests if a `value` is a prime number. ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isPrime( 5.0 ); // returns true bool = isPrime( new Number( 5.0 ) ); // returns true bool = isPrime( 3.14 ); // returns false bool = isPrime( -5.0 ); // returns false bool = isPrime( NaN ); // returns false bool = isPrime( null ); // returns false ``` #### isPrime.isPrimitive( value ) Tests if a `value` is a primitive prime number. ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isPrime.isPrimitive( 5.0 ); // returns true bool = isPrime.isPrimitive( new Number( 5.0 ) ); // returns false ``` #### isPrime.isObject( value ) Tests if a `value` is a `Number` object having a value which is a prime number. ```javascript var Number = require( '@stdlib/number/ctor' ); var bool = isPrime.isObject( 5.0 ); // returns false bool = isPrime.isObject( new Number( 5.0 ) ); // returns true ```
## Examples ```javascript var Number = require( '@stdlib/number/ctor' ); var isPrime = require( '@stdlib/assert/is-prime' ); var bool = isPrime( 5.0 ); // returns true bool = isPrime( new Number( 5.0 ) ); // returns true bool = isPrime( 11.0 ); // returns true bool = isPrime( 2.0 ); // returns true bool = isPrime( 3.14 ); // returns false bool = isPrime( -5.0 ); // returns false bool = isPrime( NaN ); // returns false bool = isPrime( '0.5' ); // returns false bool = isPrime( null ); // returns false ```