In mathematics a primitive abundant number is an abundant number whose proper divisors are all deficient numbers.
[1][2] For example, 20 is a primitive abundant number because: The first few primitive abundant numbers are: The smallest odd primitive abundant number is 945.
A variant definition is abundant numbers having no abundant proper divisor (sequence A091191 in the OEIS).
Every multiple of a primitive abundant number is an abundant number.
Every abundant number is a multiple of a primitive abundant number or a multiple of a perfect number.