aleph-null
even number
extended real number system
refactorable
duodecillionth
algebraic integer
characteristic
irrational number
complex number
imaginary number
complex quantity
imaginary
countably
aleph-one
Copeland-Erdős constant
arithmetical set
number-theoretic function
multiperfect
hyperperfect number
binary
uncountably
Prouhet-Tarry-Escott problem
Narayana number
aliquot part
random number
decillionth
aliquot
prime number theorem
overprime
fraction
real number line
amicable number
common fraction
friendly number
hyponormal
Dickson's conjecture
simple fraction
noncototient
ordinal number
Blum integer
hyperreal number
noninteger
Cauchy sequence
twin prime
singularly
undecillionth