Math Characters - copy and paste them

− + ± × ÷ ≠ ≈ ≤ ≥ ∞ ⅛ ¼ ½ ¾ ⅓ ⅔ ⅕ ⅖ ⅗ ⅘ ⅙ ⅚ ⅜ ⅝ ⅞ ∫ ∂ ∆ ∏ ∐ ∑ √ ∛ ∜ ∟ ∩ ∙ ƒ ƒ ‴

x² a₁₃ ∫ ∈ ∃ ⊆ ≣ ℝ ∪ ⋂

GREEK ALPHABET Α Β Γ Δ Ε Ζ Η Θ Ι Κ Λ Μ Ν Ξ Ο Π Ρ Σ Τ Υ Φ Χ Ψ Ω Ϊ

greek alphabet α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ ς σ τ υ φ χ ψ ω ϑ ϒ ϖ

π • … ′ ″ ‾ ⁄ ¡ ¢ £ ¤ ¥ ¦ § ¨ © ª « ¬ ­ ® ¯ ° ± ² ³ ´ µ ¶ · ¸ ¹ º »

⁐ ⁉ ⁔ ⁚ ℵ ℘ ′ ℝ ℂ ℕ ℙ ℚ ℤ

Assorted arrows, etc. ← → ↓ ↑ ↔ ↵ ⇐ ⇑ ⇒ ⇓ ⇔ ‾ ← → ↑ ↓ † ‡ • … ✔

∀ ∂ ∃ ∅ ∄ ∇ ∈ ∉ ∋ ∌ ∍ ∏ ¬

∑ ∗ √ ∝ ∞ ∠ ∧ ⊻ ⊼ ⊽ ∨ ∩ ∪ ∫ ∴ ∼

< > ≅ ≈ ≠ ≡ ≤ ≥ ⊂ ⊃ ⊄ ⊅ ⊈ ⊉ ⊊ ⊋ ⋄ ⊆ ⊇ ⊕ ⊗ ⊝ ⋅

Superscripts ⁰ ⁱ 2 3 ⁲ ⁳ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁺ ⁻ ⁼ ⁽ ⁾ ⁿ ⁱ ¹ ² ³

Subscripts ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₊ ₋ ₌ ₍ ₎ ₏ ₐ ₑ ₒ ₓ ₔ ₕ ₖ ₗ ₘ ₙ ₚ ₛ ₜ

Fractions ¼ ½ ¾ Or imitate a fraction by using a superscript integer ⁄ subscript integer - e.g. 319
(Note that &frasl; was used as the slash, not the regular / because it's tilted a bit more to the horizontal.)

ᵢ ᵣ ᵤ ᵥ ₓ ᵥ ᵦ ᵧ ᵨ ᵩ ᵪ

⌈ ⌉ ⌊ ⌋ ⊤ ⊥ ⊦ ⊦ ⊧ 〈 〉 ◊ ♠ ♣ ♥ ♦

x̄ x̂ ° µ ‰ ‱ ′ ∫ ∂ ∆ ∇ ∬ ∭ ⨌ ∮ ∯ ∰ ∱ ∲ ⨑ ∳ ℘

Non-Math

♀ ♂ ☈ ♠ ♡ ♢ ♣

Another list of mathematical symbols

Yet another list

One more