No. The first two "perfect numbers" are 6 and 28.
5 and 2 are perfect numbers
The only two are 9 and 16.
81. They are the perfect squares of numbers starting from 5.81. They are the perfect squares of numbers starting from 5.81. They are the perfect squares of numbers starting from 5.81. They are the perfect squares of numbers starting from 5.
Perfect squares are positive. A smallest negative number doesn't exist. The four smallest prime numbers are 2, 3, 5 and 7. The smallest perfect square would have to be 2^2 x 3^2 x 5^2 x 7^2 or 44,100
5 and 10 or 5 and any multiple of 5 for a start
Since the number 10 has the prime factorization of 2 x 5, any multiple of 10 has the numbers 2 and 5 in their prime factorization.
Perfect numbers are numbers where all the factors add to that number. For example 6's factors are 1,2, and 3 and 1+2+3=6. Therefore the next perfect number isn't until 28 which is 1,2, 4, 7, 14 where 1+2+4+7+14= 28 An almost perfect number is a number which, when adding all of its proper divisors (all divisors except himself), gives you one less, or one more then the number itlself. Up to now all known almost perfect numbers are 2^n. So to answer your question, the 2 almost perfect numbers between 5 and 20 are 8 and 16. Divisors of 8: 1,2,4 -----> 1+2+4=7 Divisors of 16: 1,2,4,8 -----> 1+2+4+8=15
A rational number can be expressed as a fraction, with whole numbers in the numerator and the denominator, for example 2/3, -3/4, or 5 (which is equal to 5/1). An irrational number can not be expressed as such a fraction. For example, the square root of 2, the square root of any positive integer that is not a perfect square, pi, the number e.
It could be any one of them. 5: The smallest prime number with a composite on either side. 2: The only even prime number. 8: The only perfect cube number. 13: The only 2-digit prime. 16: The only perfect square number.
Yes. The only known almost perfect numbers are the powers of 2. 32 = 2^5 is an almost perfect number. It has not yet been proved whether {x: x = 2^n for n in N} = {x: x is an almost perfect number}.
That could either be "What numbers have 5 factors" or "What numbers have 2 and 5 as factors." Prime numbers to the fourth power, like 16 and 81, have 5 factors. Any multiple of 10 has 2 and 5 as a factor.
There are infinitely many, just like in base 10. In any base system, the number of perfect squares is the same. Take the natural (counting) numbers 1, 2, 3, .... Squaring each of these produces the perfect squares. As there are an infinite number of natural numbers, there are an infinite number of perfect squares. The first 10 perfect squares in base 5 are: 15, 45, 145, 315, 1005, 1215, 1445, 2245, 3115, 4005, ...