Which of the following is a prime number?

Which one of the following cannot be the square of a natural number?

Consider the following numbers : 1. 437 2. 797 3. 1073 How many of the above numbers are prime ?

What is the digit at the 100th place of number (225)⁴⁰ ?

The value of a 2-digit number is 5 times the sum of the digits. What is the product of the digits ?

Consider the following statements in respect of all factors of 360 : 1. The number of factors is 24. 2. The sum of all factors is 1170. Which of the above statements is/are correct?