According to the number of divisors, natural numbers can be divided into: (1) prime numbers and composite numbers; (2) odd numbers and even numbers; (3) prime numbers, composite numbers and zero ④ Prime, composite and 1

According to the number of divisors, natural numbers can be divided into: (1) prime numbers and composite numbers; (2) odd numbers and even numbers; (3) prime numbers, composite numbers and zero ④ Prime, composite and 1

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