text: The characteristic of a field always has this property. The Meissel-Mertens constant relates log of log of n tothe partial sums of the reciprocals of numbers with this property.
full_question: The characteristic of a field always has this property. The Meissel-Mertens constant relates log of log of n tothe partial sums of the reciprocals of numbers with this property. The log of a number with this property is theoutput when a number n, that is a power of a number with this property, is input to the von Mangoldtfunction. n minus one factorial equals negative one mod n only if n has this property, by Wilson's theorem.Carmichael numbers do not have this property, but nonetheless can serve as the modulus in Fermat's littletheorem. The number of them less than n is approximately n over log of n. Euclid proved their infinitude. For10 points, name these numbers only divisible by one and themselves. 
first_sentence: The characteristic of a field always has this property. The Meissel-Mertens constant relates log of log of n tothe partial sums of the reciprocals of numbers with this property.
raw_answer: prime numbers