On grammatical class:

ci'i
digit/number: infinity; followed by digits => aleph cardinality.
ka'o
digit/number: imaginary i; square root of -1.
no'o
digit/number: typical/average value.
pai
digit/number: pi (approximately 3.1416...); the constant defined by the ratio of the circumference to the diameter of all circles.
te'o
digit/number: exponential e (approx 2.71828...).
tu'o
null operand (used in unary mekso operations).
fai'e'au
digit/number: first Feigenbaum constant δ = 4.669 201 609 102 990 671 853 203 821 578(...).
fai'u
digit/number: phi, the "golden ratio" (approx. = 1.6180...); the ratio a/b such that it equals (a+b)/a
fai'u'a
digit/number: the fine-structure constant \alpha \approx 7.2973525698(\dots)×10(-3) \approx 1/137.035999074.
fu'a'ai
digit/number: first Foias' constant; the unique value of x1 such that xn -> ∞ as n -> ∞ for xn+1 = (1 + (1/( xn )))^n; such x1 = 1.187…
fu'a'au
digit/number: second Foias constant; the value x for which (1/x)(1 + (1/x))x=1 is true; ≈ 2.293…
ga'au
digit/number: Euler–Mascheroni constant, usually denoted by lowercase gamma (γ); approximately 0.5772156649 (in decimal).
gau'i'o
digit/number: Gauss' arithmetic-geometric mean of 1 and √(2) constant G ≈ .8346268…
go'o'i'a
digit/number: Goloumb-Dickman constant ≈ .6243…
ka'ei'a
digit/number: Conway's look-and-say constant λ ≈ 1.303577269…
kai'o
quaternion i
ka'o'ai
imaginary i (non-comma)
ka'o'ei
imaginary i, comma - spherical coordinates: first coordinate gives magnitude (complex modulus/radius) of the number, the second number gives the angle from the positive real axis measured counterclockwise toward the 'positive' imaginary axis (default: in the primary branch/Arg) as measured in some units (which that number should contain; the contextless default will suppose radians); the angle is not normalized.
kau'o
generic algebra unit en
kei'o
quaternion j
koi'o
quaternion k
mai'e'e
digit/number: Meissel-Mertens constant M ≈ 0.2614972128476427837554268386086958590516…
mu'i'ai
digit/number: Hafner-Sarnak-McCurley coprime determinants limiting probability constant; h ≈ 0.3532363719…
na'a'u
not a number
ni'e'ei
digit/number: Niven's greatest-exponent prime factorization constant lim(n->∞) (avg
ni'e'oi
digit/number: Niven's smallest-exponent prime factorization constant c = zeta(3/2)/zeta(3) ≈ 2.1732543125195541382370898404…
pa'au'o
digit/number: universal parabolic constant P = √(2) + Loge(1 + √(2)) ≈ 2.295587
pei'i'a
digit/number: Apéry's constant ζ(3) = 1.202056903159594285399738161511449990764986292…
pu'e'u'o
digit/number: the Prouhet-Thue-Morse constant τ = 0.412454033640… (in decimal)
se'i'i
digit/number: Sierpiński constant K = π(2 Loge(2) + 3Log
sei'u'e
digit/number: ideal first Skewe's constant Sk1 ; the first (minimal positive) infimum for which all greater x in some neighborhood have the property that it is false that the prime counting function at x is less than the logarithmic integral function at x
tau'u
digit/number: tau (approximately 6.2831...). The constant defined by the ratio of the circumference to the radius of all circles.
va'ei'a
digit/number: Dom Hans van der Laan's plastic number ρ = 1.324717957244746025960908854…
vau'au'o
omega constant, Lambert product-log W(1)
vi'ei'e
digit/number: Lévy-Khinchin constant γ = e^(π^2)/(12Loge(2)) ≈ 3.2758…
vo'ei'a
digit/number: Lambert W(1) constant Ω ≈ 0.5671432904097838729999686622…
xi'i'ei
digit/number: Khinchin's constant K0 = 2.6854520010…