What is the simplified form of ∛218?

The cube root of 218 is already in simplest form: ∛218 ≈ 6.0185. Since 218 has no perfect cube factors greater than 1, it cannot be simplified further.

How do you simplify the cube root of 218?

To simplify ∛218, find the prime factorization of 218, group the factors in triples (groups of three), and move each complete triple outside the radical sign. Any factors not part of a complete triple remain inside.

Is ∛218 rational or irrational?

∛218 is irrational. Although it can be written in the simplified radical form ∛218, its decimal expansion (6.0185...) never terminates or repeats.

Simplify the Cube Root of 218 = ∛218

Quick Answer

∛218 = ∛218 (≈ 6.0185)

Formula: 218 has no perfect-cube factor > 1 → ∛218 is already simplest

Simplify Cube Root Calculator

Simplify ∛ Cube Root Cubed (n³) Is N a Perfect Cube?

Use the calculator above to simplify any cube root to its simplest radical form (e.g. ∛24 = 2∛3). See below the step-by-step method using prime factorization, plus a table of common simplified cube roots.

Step-by-Step: Simplify ∛218

To simplify ∛218, find the largest perfect cube that divides 218:

218 = 1 × 218
∛218 = ∛1 × ∛218
∛218 = ∛218

In decimal form: ∛218 ≈ 6.0185

See prime factorization details

Prime factorization: 218 = 2 × 109

Group the identical primes in triples (three of a kind); each complete triple contributes one factor outside the radical, and any leftovers (1 or 2 of the same prime) stay inside.

Formula

To rewrite any cube root in simplest radical form:

∛(a³ · b) = a · ∛b

Where:

a³ = the largest perfect-cube factor of the radicand (the number under the ∛ symbol)
b = the remaining cubefree factor (no perfect cube divides it other than 1)

Worked example for ∛24:

24 = 8 × 3 = 2³ × 3
So a³ = 8, a = 2, b = 3
Therefore ∛24 = 2∛3

How to Simplify Cube Roots

Simplifying a cube root means rewriting it in the simplest radical form, where the number under the radical (the radicand) has no perfect cube factors other than 1.

Method: Prime Factorization

Find the prime factorization of the radicand.
Identify triples (groups of three) of identical prime factors.
Each complete triple contributes one factor outside the radical.
Any prime factor not part of a complete triple (1 or 2 leftovers) stays under the radical.

Example: Simplify ∛128

128 = 2 × 2 × 2 × 2 × 2 × 2 × 2 = 2⁷
We have two complete triples of 2's (2³ × 2³) plus a leftover 2.
Each triple → contributes one 2 outside. Two triples → 2 × 2 = 4 outside. The leftover 2 stays inside.
∛128 = 4∛2

Nearby Simplified Cube Roots

Click any value to see the full step-by-step solution.

∛n	Simplified	≈ Decimal
∛108	3∛4	4.7622
∛125	5	5.0000
∛128	4∛2	5.0397
∛135	3∛5	5.1299
∛162	3∛6	5.4514
∛189	3∛7	5.7388
∛192	4∛3	5.7690
∛216	6	6.0000
∛243	3∛9	6.2403
∛250	5∛2	6.2996
∛256	4∛4	6.3496
∛320	4∛5	6.8399

Want the Decimal Value Instead?

If you want the decimal approximation (e.g. ∛24 ≈ 2.8845) with the Newton's Method step-by-step, use our Cube Root Calculator.

Is 218 Itself a Perfect Cube?

If the radicand 218 is itself a perfect cube (e.g. 216 = 6³), then ∛218 simplifies to an integer. Check with our Perfect Cube Checker for the verdict + prime-factorization proof.

References

Popular Simplified Cube Roots

Top cube root simplifications — click any to see the step-by-step solution: