940 is not a prime number.

A prime number has only two positive divisors: 1 and itself.

For 940, the positive divisors are :

• 1 is a divisor of 940 : $940 / 1 = 940$
• 2 is a divisor of 940 : $940 / 2 = 470$
• 4 is a divisor of 940 : $940 / 4 = 235$
• 5 is a divisor of 940 : $940 / 5 = 188$
• 10 is a divisor of 940 : $940 / 10 = 94$
• 20 is a divisor of 940 : $940 / 20 = 47$
• 47 is a divisor of 940 : $940 / 47 = 20$
• 94 is a divisor of 940 : $940 / 94 = 10$
• 188 is a divisor of 940 : $940 / 188 = 5$
• 235 is a divisor of 940 : $940 / 235 = 4$
• 470 is a divisor of 940 : $940 / 470 = 2$
• 940 is a divisor of 940 : $940 / 940 = 1$

Since 940 is divisible by 2, 4, 5, 10, 20, 47, 94, 188, 235 and 470, it has divisors other than 1 and itself.

Therefore, 940 is not a prime number.