Numbers and Constants Symbols: Names, Meanings and LaTeX Codes
This cheat sheet lists 15 Numbers and Constants symbols from nyuyo. It includes aleph-null, complex-numbers, euler-mascheroni and more. Each entry shows the symbol, its meaning, LaTeX command, Unicode code point and HTML entity. Every entry also shows how to read an example aloud.
aleph-null
Character
ℵ₀
Name
Aleph Null
Meaning
The cardinality of the natural numbers, the smallest infinite size a set can have. Any set this size is called countable.
LaTeX
\aleph_0
Unicode
U+2135 U+2080
HTML entity
ℵ₀
Example expression
|ℕ| = ℵ₀
Read aloud
the cardinality of the natural numbers is aleph null
Related symbols
Natural Numbers, Infinity
complex-numbers
Character
ℂ
Name
Complex Numbers
Meaning
The set of all numbers a + bi where a and b are real and i² = −1. Every polynomial equation has a solution in it.
LaTeX
\mathbb{C}
Unicode
U+2102
HTML entity
ℂ
Example expression
z ∈ ℂ
Read aloud
z is a complex number
Related symbols
Real Numbers, Imaginary Unit, Quaternions, Element Of
euler-mascheroni
Character
γ
Name
Euler–Mascheroni Constant
Meaning
The limit of 1 + 1/2 + ⋯ + 1/n − ln n as n grows without bound, approximately 0.57722. It is not known whether it is irrational.
LaTeX
\gamma
Unicode
U+03B3
HTML entity
γ
Example expression
γ ≈ 0.57722
Read aloud
gamma is approximately zero point five seven seven two two
Related symbols
Gamma, Euler's Number, Summation, Approximately Equal
eulers-number
Character
e
Name
Euler's Number
Meaning
The base of the natural logarithm, approximately 2.71828. It is the limit of (1 + 1/n)ⁿ as n grows without bound.
LaTeX
e
Unicode
U+0065
HTML entity
e
Example expression
e^(iπ) + 1 = 0
Read aloud
e to the i pi, plus one, equals zero
Related symbols
Pi, Imaginary Unit
golden-ratio
Character
φ
Name
Golden Ratio
Meaning
The number (1 + √5)/2, approximately 1.61803. It is the positive solution of x² = x + 1.
LaTeX
\varphi
Unicode
U+03C6
HTML entity
φ
Example expression
φ = (1 + √5)/2
Read aloud
phi equals one plus root five, over two
Related symbols
Pi, Euler's Number
imaginary-unit
Character
i
Name
Imaginary Unit
Meaning
A number whose square is −1. Complex numbers are written as a + bi with a and b real. In engineering it is often written j.
LaTeX
i
Unicode
U+0069
HTML entity
i
Example expression
i² = −1
Read aloud
i squared equals minus one
Related symbols
Euler's Number, Real Numbers, Square Root
infinity
Character
∞
Name
Infinity
Meaning
Describes something without bound. It is not a real number; it appears in limits, intervals, and sums that continue forever.
LaTeX
\infty
Unicode
U+221E
HTML entity
∞
Example expression
x → ∞
Read aloud
x tends to infinity
Related symbols
Right Arrow, Summation, Integral, Euler's Number
integers
Character
ℤ
Name
Integers
Meaning
The set of whole numbers: the positive whole numbers, their negatives, and zero.
LaTeX
\mathbb{Z}
Unicode
U+2124
HTML entity
ℤ
Example expression
k ∈ ℤ
Read aloud
k is an integer
Related symbols
Natural Numbers, Real Numbers
natural-numbers
Character
ℕ
Name
Natural Numbers
Meaning
The set of counting numbers 1, 2, 3, and so on. Some authors include 0, so check the convention in use.
LaTeX
\mathbb{N}
Unicode
U+2115
HTML entity
ℕ
Example expression
n ∈ ℕ
Read aloud
n is a natural number
Related symbols
Integers, Real Numbers, Element Of
pi
Character
π
Name
Pi
Meaning
The ratio of a circle's circumference to its diameter, approximately 3.14159. It is an irrational number.
LaTeX
\pi
Unicode
U+03C0
HTML entity
π
Example expression
C = 2πr
Read aloud
C equals two pi r
Related symbols
Euler's Number, Degree, Theta, Approximately Equal
prime-numbers
Character
ℙ
Name
Prime Numbers
Meaning
The set of prime numbers, the whole numbers greater than 1 whose only divisors are 1 and themselves. The same letter is also used for probability and projective space.
LaTeX
\mathbb{P}
Unicode
U+2119
HTML entity
ℙ
Example expression
7 ∈ ℙ
Read aloud
seven is a prime number
Related symbols
Natural Numbers, Integers, Vertical Bar, Element Of
quaternions
Character
ℍ
Name
Quaternions
Meaning
The number system a + bi + cj + dk with real a, b, c, d and i² = j² = k² = ijk = −1. Multiplication is not commutative. The letter honors Hamilton.
LaTeX
\mathbb{H}
Unicode
U+210D
HTML entity
ℍ
Example expression
q ∈ ℍ
Read aloud
q is a quaternion
Related symbols
Complex Numbers, Real Numbers
rational-numbers
Character
ℚ
Name
Rational Numbers
Meaning
The set of all fractions p/q where p and q are integers and q is not zero. The letter comes from quotient.
LaTeX
\mathbb{Q}
Unicode
U+211A
HTML entity
ℚ
Example expression
1/2 ∈ ℚ
Read aloud
one half is a rational number
Related symbols
Integers, Real Numbers, Natural Numbers, Element Of
real-numbers
Character
ℝ
Name
Real Numbers
Meaning
The set of all numbers on the number line, including fractions and irrational numbers such as √2 and π.
LaTeX
\mathbb{R}
Unicode
U+211D
HTML entity
ℝ
Example expression
x ∈ ℝ
Read aloud
x is a real number
Related symbols
Integers, Natural Numbers
square-root-of-two
Character
√2
Name
Square Root of Two
Meaning
The positive number whose square is 2, approximately 1.41421. It is the length of a unit square's diagonal and was the first number shown to be irrational.
LaTeX
\sqrt{2}
Unicode
U+221A U+0032
HTML entity
√2
Example expression
(√2)² = 2
Read aloud
root two, squared, equals two
Related symbols
Pi
FAQ
How many Numbers and Constants symbols are on this page?
This page lists 15 Numbers and Constants symbols, including aleph-null, complex-numbers, euler-mascheroni.
How do I type Numbers and Constants symbols in LaTeX?
Each symbol on this page has its LaTeX command shown next to it, for example \aleph_0, \gamma, \infty. Copy the command into your maths mode.
What are the Unicode code points for Numbers and Constants symbols?
Every symbol lists its Unicode code point, such as U+0065, U+0069, U+03B3, so you can insert it in documents and web pages.
How do I write Numbers and Constants symbols in HTML?
Each entry shows its HTML entity where one exists, for example ℵ₀, ℂ, γ. You can paste it directly into your page.
How do I read Numbers and Constants symbols aloud?
Each symbol has an example expression and a spoken version, such as (√2)² = 2, |ℕ| = ℵ₀, 1/2 ∈ ℚ read as C equals two pi r, e to the i pi, plus one, equals zero, gamma is approximately zero point five seven seven two two.