What is the Least Composite Number?

The Least (Smallest) Composite Number is 4. To understand why, we need to clearly define what composite numbers are.

Question (Click to Flip)

Is 1 a composite number?

Answer

No. 1 is neither prime nor composite. A composite number must have more than 2 factors. Since 1 has only one factor (itself), it does not qualify as composite.

Card 1 of 1 free previews

Key Facts

The list of composite numbers begins: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20... Note that all even numbers (except 2) are composite. Odd composites are less common: 9, 15, 21, 25, 27...

Definition of Composite Numbers

A Composite Number is a positive integer greater than 1 that has at least one positive divisor other than 1 and itself — i.e., it can be divided evenly by some number other than 1 and the number itself.

In other words, a composite number has 3 or more factors.

Examples:

4 = 1 × 4 and 2 × 2 → factors: 1, 2, 4 → Composite ✓
6 = 1 × 6 and 2 × 3 → factors: 1, 2, 3, 6 → Composite ✓
2 = 1 × 2 only → Prime (not composite)
3 = 1 × 3 only → Prime (not composite)

Why 4 is the Least Composite Number

Checking small numbers:

1: Has only 1 factor (1 itself). It is neither prime nor composite.
2: Has exactly 2 factors (1 and 2). It is a prime number (the only even prime).
3: Has exactly 2 factors (1 and 3). It is a prime number.
4: Has 3 factors (1, 2, and 4). It is composite ✓

Since 4 is the first number with more than 2 factors, 4 is the least composite number.

Questions and Answers

Is 1 a composite number?+

No. 1 is neither prime nor composite. A composite number must have more than 2 factors. Since 1 has only one factor (itself), it does not qualify as composite.

More in Maths

📐

Represent 1.3 on Number Line

How to represent 1.3 on a number line — Class 9 Maths. Step-by-step method: divide the segment between 1 and 2 into 10 equal parts; 3rd part = 1.3.

📐

सम संख्या और विषम संख्या किसे कहते हैं? (Even & Odd Numbers)

गणित (Maths): सरल हिंदी में जानें सम संख्या (Even Numbers) और विषम संख्या (Odd Numbers) किसे कहते हैं, और इनकी पहचान कैसे करें।

📐

शंकु का आयतन (Volume of a Cone)

जानें शंकु का आयतन (Volume of a Cone) निकालने का सूत्र। बेलन और शंकु के आयतन में क्या संबंध है? कक्षा 9 और 10 गणित के लिए महत्वपूर्ण सूत्र।

📐

What is the Value of sec 60°?

sec 60° = 2. Because cos 60°=1/2 and sec=1/cos, so sec 60°=1/(1/2)=2. cosec 60°=2/√3, cot 60°=1/√3. Complete trig table at 60°.

📐

Self Inductance Formula – Definition and Derivation

Learn the exact formula for Self Inductance of a coil. Understand how L = μ₀n²V is derived and what affects the self-inductance of a solenoid.

Study Smarter with Shinyu.ai

Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.