Set Prime vales equal to zero

Given matrix

x=[10 12 36 78 92;11 14 57 74 91;40 38 29 72 81;34 27 39 48 62;10 14 18 82 73]

, how can I create a new matrix "xnp" that sets all non-prime elements equal to 0?

Answer 1

[Fangjun Jiang]

isprime()