The factors of 90 are one, two, three, five, six, nine, 10, 15, 18, 30, 45 and 90. Factors are whole number that can divide into another number leaving no remainder (no decimals).
When determining the factors of a number, it is often necessary to first divide the number by two, then subsequently by increasing the divisor by a value of one until the original number is reached. The factors are any whole numbers that come from this process. If the number ends in zero, then the number has factors of two, five and ten. If the number ends in five, it has a factor of five. If the number is even, then two is a factor. If the number ends in two zeros, then 100 is a factor.