What is the square root of 21?

Answer

4.582576

21 is not a perfect square4.582576² = 4.582576² ≈ 214.582576 × 4.582576 = ≈ 21

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How We Calculated This

√n — the number which, multiplied by itself, equals n

√21 = 4.582576

Related Calculations

What is the square root of 1?1 (exact)What is the square root of 2?1.414214 What is the square root of 3?1.732051 What is the square root of 4?2 (exact)What is the square root of 5?2.236068

Calculated using verified formulas. Last updated March 2026.