512 has 9 prime factors
The largest one digit number that has three factors is 9. Its factors are 1, 3, and 9.
49
4 : with factors 1, 2 and 4
A smaller 3 digit number or a 2 digit number (99).
If factors include 1 and the number itself then the any number (n) with only 4 factors has to be the product of two prime numbers, p1 and p2. The factors are then n, p1, p2, and 1. The largest 3-digit number with only 4 factors is 998. The factors are 998, 499, 2 and 1
The largest one digit number that has three factors is 9. Its factors are 1, 3, and 9.
The squares of most 2 digit prime numbers. For example 2809, which is the square of 53, has 3 factors : 1, 53 and 2809 itself.
240
840
The one digit number that has the same number of factors as the number six is three. Six's factors are 1, 2, 3, and 6 while three's factors are 1 and 3. Therefore, both numbers have the same number of factors.
The greatest product you can achieve by multiplying a 3-digit number by a 1-digit number is 9720, which comes from multiplying 972 (the largest 3-digit number less than 1000 when divided by 9) by 9 (the largest 1-digit number). Thus, the factors are 972 and 9.
625 has five factors.
There are many 4 digit numbers having 3 and 11 as factors. One of them is 1089 whose factors are 3,3,11,11.
There are none but the smallest 3 digit number is 161
100
9409
The largest two-digit number that has exactly three factors is 99. A number has exactly three factors if it is the square of a prime number. In this case, ( 9 = 3^2 ) has three factors: 1, 3, and 9. However, since 99 is the largest two-digit number, we consider its factors, but it does not meet the criterion. The correct answer is 81, which is ( 9^2 ).