Divisor Count of 40,313

Example of Use of Divisor Count Function

$\map {\sigma_0} {40 \, 313} = 8$

where $\sigma_0$ denotes the divisor count function.

Proof

From Divisor Count Function from Prime Decomposition:

$\ds \map {\sigma_0} n = \prod_{j \mathop = 1}^r \paren {k_j + 1}$

where:

$r$ denotes the number of distinct prime factors in the prime decomposition of $n$

$k_j$ denotes the multiplicity of the $j$th prime in the prime decomposition of $n$.

We have that:

$40 \, 313 = 7 \times 13 \times 443$

Thus:

\(\ds \map {\sigma_0} {40 \, 313}\)

\(=\)

\(\ds \map {\sigma_0} {7^1 \times 13^1 \times 443^1}\)

\(\ds \)

\(=\)

\(\ds \paren {1 + 1} \paren {1 + 1} \paren {1 + 1}\)

\(\ds \)

\(=\)

\(\ds 8\)

The divisors of $40 \, 313$ can be enumerated as:

$1, 7, 13, 91, 443, 3101, 5759, 40 \, 313$

$\blacksquare$