It belongs to an infinite number of sets.
For example the sets of:
Irrational and transcendental
fractions
Any set of numbers that contain them! For example, they belong to the set {10, 11} or {10, 11, sqrt(2), pi, -3/7}, or {10, 11, bananas, France, cold} or all whole numbers between 3 and 53, or counting numbers, or integers, or rational numbers, or real numbers, or complex numbers, etc.
Integers. (This includes negative whole numbers.)
The integers. Also: the rational numbers, the real numbers and (depending on your definition) the complex numbers.
The set of numbers which 3 does not belong is the set of even numbers.
10 belongs to the set "natural numbers", but it can also belong to whole numbers, and rational numbers
Natural (counting) numbers; integers; rational numbers; real numbers; complex numbers. And any other set that you choose to define, that happens to include the number 4 - for example, the set of square numbers, or even numbers, the set of the numbers {3, 4, 5, 7, 14, 48}, etc, the set of numbers containing the letter o in their English name.
Counting numbers
Irrational numbers.
The set of even numbers
The numbers that belong to the series are the following: 1, 2, 5, 10, 13, 26, 29 and 48.
It belongs to the set of prime numbers
Rational and Real numbers
rational and prime numbers
mixed numbers
Negative numbers belong to the set of integers, which includes all whole numbers and their negative counterparts. They are also part of the set of rational numbers, as they can be expressed as fractions. Additionally, negative numbers are included in the set of real numbers, which encompasses all rational and irrational numbers.