👉 In mathematics, a trillionth is a very small number that represents one part in a million. It's denoted as 1/10^6 or 10^-6. For example: - 1 trillionths would be 0.000001. - 2 trillionths would be 0.0000001. - 3 trillionths would be 0.00000001. These are very small