9514 1404 393
Answer:
multiple solutions, see the attachment
Explanation:
If you allow any digits 0-9, there are 11 possible solutions. Of these, two have the leading digit O = 0, so you may not agree that is an allowable solution.
Each row in the attachment is a possible solution. (Rows 4 and 10 have O=0.)
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Found by exhaustive search using a computer program. Note that E=7 and N=1 are not hard to find by hand.