88
-- List the digits that are used to write the number. -- Add up the list.
The single-digit factors of 2100 are 1, 2, 3, 4, 5, 6, 7, 8, and 9. However, among these, the actual factors of 2100 are 1, 2, 3, 4, 5, 6, and 7. The number 8 and 9 are not factors of 2100. Thus, the complete list of single-digit factors is 1, 2, 3, 4, 5, 6, and 7.
3 13 23 43 53 73 83
1, 11, 21, 31, 41. 1 is not a prime number.
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
6677
-- List the digits that are used to write the number. -- Add up the list.
The single-digit factors of 2100 are 1, 2, 3, 4, 5, 6, 7, 8, and 9. However, among these, the actual factors of 2100 are 1, 2, 3, 4, 5, 6, and 7. The number 8 and 9 are not factors of 2100. Thus, the complete list of single-digit factors is 1, 2, 3, 4, 5, 6, and 7.
3 13 23 43 53 73 83
1, 11, 21, 31, 41. 1 is not a prime number.
Nope, look at 1000, this is a 4 digit number and we can't list it with 1,2,3, and 4
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
8
The list of factors of a number is a list of numbers that divide evenly into it. A list of multiples of a number is just a list of numbers that the first number divides. Example Factors of 6: 1,2,3,6 Multiples of 6: 6,12,18...
The hundreds digit is 2; the tens digit is 5; the ones digit is 8; the tenths digit is 1; the hundredths digit is 7; the thousandths digit is 6.
When you are finding common factors, one method is to list the factors.
The proper factors of a number are all the factors less than itself, so the proper factors of 126 are 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, and 63. In some cases, the number 1 is excluded from the list of proper factors, too.