No, they are two words, as in the question.
Number notation = 1,000 Word notation = one thousand.
I love the word thousand, When I grow up I want to get One Thousand dollars
Three thousand one hundred Thirty-one hundred
The word millennia means one thousand years. It refers to a span of one thousand years or even a one thousand year anniversary. Millennium refers to the thousand years that Christ will reign on earth.
Forty-one thousand, twenty
one hundred fifty thousand
one thousand = élef (אלף)
Kilo
One thousand.
one thousand and sixty-four
1400 in word form is "fourteen hundred" or "one thousand four hundred."
Fifty-one thousand, one.