Low level put_item changing number format into DynamoDB. Is this a bug?

[NatxoM]

I have this data to entry into AWS DynamoDB:

item = {
    "PK": {
        "S": "DEBUG"
    },
    "SK": {
        "S": "#ID_LOG#2025-10-09T07:48:31.105674+00:00"
    },
    "data": {
        "M": {
            "t": {
                "N": "1.00000000000000007629769841092E+50"
            }
        }
    },
    "ttl": {
        "N": "1759999711"
    }
}

I use this code to put it into the table:

db_client = boto3.client('dynamodb')
response = db_client.put_item(
    TableName = "mytable",
    Item = item
)

But the data inserted in the table is:

{
 "PK": {
  "S": "DEBUG"
 },
 "SK": {
  "S": "#ID_LOG#2025-10-09T07:48:31.105674+00:00"
 },
 "data": {
  "M": {
   "t": {
    "N": "100000000000000007629769841092000000000000000000000"
   }
  }
 },
 "ttl": {
  "N": "1759999711"
 }
}

Why? Is this a bug?

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