Any integer (not a fraction) that cannot be divided exactly by 2. 
The last digit is 1, 3, 5, 7 or 9.
Example: −3, 1, 7 and 35 are all odd numbers.

Operators are the constructs which can manipulate the value of operands.
Consider the expression 4 + 5 = 9. Here, 4 and 5 are called operands and + is called operator.
Operators are

• arithmetic : +, -, *, /, **,
  
• comparison : > , <, ==, !=, >=, <=
• boolean: AND, OR, NOT, XOR, NOR, NAND, XNOR