# 63973

$t_title is "63973"

$t_adjust_path is "/~caldwell/curios/"

$t_class is "composite"

$short is "63973"

$nunber_id is "5328"

$t_meta['description'] is "One of many pages of prime number
curiosities and trivia. This page discusses 63973
Come explore a new prime today!"

63973 = 7 x 13 x 19 x 37, is the first Carmichael number to have 4 prime factors with entirely odd digits (totalling 7 digits, with 7 being one of those factors). The sum of those prime factors is 76 = 2^2 x 19, hence the mean of the prime factors is 19, which is one of those factors. Exactly half of the first 12 Carmichael numbers have entirely odd digits in each of their 3 prime factors. [Carmichael]

(There is one curio for this number that has not yet been approved by an editor.)

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