A prime factor is a factor that is prime, i.e., one that cannot itself be factored. In general, a prime factorization takes the form
where
are prime factors and
are their orders. prime factorization can
be performed in the Wolfram Language
using the command FactorInteger[n],
which returns a list of
pairs.
The following table gives the prime factorization for the positive integers .
| prime fac. | prime fac. | prime fac. | prime fac. | prime fac. | |||||
| 1 | 1 | 11 | 11 | 21 | 31 | 31 | 41 | 41 | |
| 2 | 2 | 12 | 22 | 32 | 42 | ||||
| 3 | 3 | 13 | 13 | 23 | 23 | 33 | 43 | 43 | |
| 4 | 14 | 24 | 34 | 44 | |||||
| 5 | 5 | 15 | 25 | 35 | 45 | ||||
| 6 | 16 | 26 | 36 | 46 | |||||
| 7 | 7 | 17 | 17 | 27 | 37 | 37 | 47 | 47 | |
| 8 | 18 | 28 | 38 | 48 | |||||
| 9 | 19 | 19 | 29 | 29 | 39 | 49 | |||
| 10 | 20 | 30 | 40 | 50 |
Two standard arithmetic functions count prime factors. The prime nu function
counts distinct prime factors, while the prime
omega function
counts them with multiplicity. For example,
gives
and
(Hardy and Wright 1979, p. 354). The notation
is also used for
, while
can denote either count, so care is needed unless the convention
is stated. The
appearing in Veritasium (2025) is instead a local notation for the number of Goldbach
partitions of
.