Yes there is such thing as two thousands in a number.
The two is in the ten-thousands place value.
Two thousandths of an inch is written 0.002"
The correct term is "two thousand." When referring to a specific quantity of thousands, you would use the singular form "thousand" followed by the specific number, such as "two thousand." The plural form "two thousands" would be incorrect in this context.
Within the range covered by "thousands" would be any number from 1000 to 99,000 - after that the range is "hundreds of thousands. However, there is no such thing as "the biggest number" as all numbers can be added to, again and again, to an unreachable infinity.
$51,200
666
There are twenty-three thousand, with two hundred remaining.
8672300
In 557,995 the number 7 is in the thousands column. Start from the right and work to the left, the number places are units, tens, hundreds, thousands, ten thousands, hundred thousands.
5.0203
60.251
The number two is a singular, common noun, word for a thing.