21 = 3 x 7
both 3 and 7 are prime numbers
No. The only factors of a prime number are 1 and itself. The only way that 21 could be a factor of a prime number is if it were a prime number, but it is not because 21 is also divisible by 3 and 7.
3 is a prime factor of 12 and of 21.
If 21 is a multiple of the number, the number cannot have 90 as a factor.
21 is not a prime factor, it is 3 x 7
3
3 and 7
7
3 and 7
They are: 3 and 7
prime factor = prime number which can be divided into the given number with no remainder The prime factors of 21 are 3 and 7.
3x7=21 3 and 7 are prime numbers, so 3x7 is the factor tree of the number 21.
3 x 7 = 21