Number System II

Factors of a Number

Representing a number as prime factors helps in analyzing problems.

Where p, q, r are prime numbers and a, b, c are the number of times each prime number occurs.

Number of Factors = (a + 1)(b + 1)(c + 1)

Number of Ways of Expressing a Given Number as a Product of Two Factors

Sum of Factors =

Concept of Cyclicity

Concept of cyclicity is used to find unit's digit in case the numbers are occuring in powers.

Cyclicity of 1, 5, 6 - 1

Cyclicity of 4, 9 - 2

Cyclicity of 2, 3, 7, 8 - 4

Maximum Power of p (prime nubmer) in n! (n factorial)

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