2821

The number 2821 is a four-digit whole number, which means it is greater than 2000 but less than 3000. It can be broken down into thousands, hundreds, tens, and ones: 2 thousands, 8 hundreds, 2 tens, and 1 one. Mathematically, it equals (2 × 1000) + (8 × 100) + (2 × 10) + 1. It's an odd number because it ends in 1, and it is not divisible by 2. It can also be expressed as a sum or in place value to understand its composition within the number system.