Find the odd number / letters / word from the given alternative: 10, 13, 234, 681, 997

[amp_mcq option1=”10″ option2=”234″ option3=”13″ option4=”681 E. 997″ correct=”option1″]

The answer is $\boxed{10}$.

All the other numbers are prime numbers, while 10 is not. A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers.