What is the largest four digit number, with just three factors?

• A number with exactly 3 factors is the square of a prime number. The largest 4-digit number that is a perfect square of a prime will be the square of the largest prime smaller than 100. That prime is 97.
  Your number is 9409. Its factors are 1, 97, and 9409.
• 12 years agoHelpfull: Yes(8) No(0)