numbers which do not make pairs are called
Friendly number A number that is not part of any friendly pair is called solitary.
Multiplication The numbers to be multiplied are generally called the "factors". The number to be multiplied is called the "multiplicand", while the number of times the multiplicand is to be multiplied comes from the "multiplier". Usually the multiplier is placed first and the multiplicand is placed second,[1] however sometimes the first factor is the multiplicand and the second the multiplier.[6] Additionally, there are some sources in which the term "multiplicand" is regarded as a synonym for "factor".[7] In algebra, a number that is the multiplier of a variable or expression (e.g., the 3 in 3xy2) is called a coefficient.