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<AgentInstructions>

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```json
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  "path": "/reference-sql/functions-reference/string/md5-number-lower64",
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> Reference material for MD5_NUMBER_LOWER64 function

# MD5_NUMBER_LOWER64

Represent the lower 64 bits of the MD5 hash value of the input string as `BIGINT`.

## Syntax

```sql theme={"theme":{"light":"github-light","dark":"github-dark"}}
MD5_NUMBER_LOWER64(<expression>)
```

## Parameters

| Parameter      | Description                                                             | Supported input type |
| :------------- | :---------------------------------------------------------------------- | :------------------- |
| `<expression>` | The string to calculate the MD5 hash value on and represent as `BIGINT` | `TEXT`               |

## Return Type

`BIGINT`

## Example

The following example represents the username `esimpson` as a `BIGINT`:

```sql theme={"theme":{"light":"github-light","dark":"github-dark"}}
SELECT
	MD5_NUMBER_LOWER64('esimpson') AS username;
```

**Returns**: `624,533,696,996,866,075`