Singularity is another name for positive odd number in mathematics, and even number is another name for positive even number in mathematics. Extended data singular number is another name for positive odd number in mathematics, as opposed to even number. Even number is another name for even number in mathematics, as opposed to odd number. In addition, singular and even have many properties, such as singular+singular = even; Even+odd = odd; Even number+even number+...+even number = even number; Odd-odd = even; Even-odd = odd; Singular-even = singular.