How Many Zeros in a Tredecillion?
A tredecillion has 42 zeros: 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000. In scientific notation, the zeros in a tredecillion equal 1042. The short-scale system used in the United States defines tredecillion as 14 groups of three zeros beyond the ones place — 3 × 14 = 42 zeros in total. The prefix tre- means three combined with dec- for ten, placing it as the 14th name in the short-scale "-illion" sequence. In the long-scale system used in parts of continental Europe, a tredecillion has 78 zeros (1078), using the same naming convention but a fundamentally different step size. Related: How many zeros in a million.
A tredecillion has
42
zeros
- Written Form
- 1 followed by 42 zeros
- Scientific
- 10⁴²
Is a Tredecillion a Real Number, and How Many Zeros Does It Have?
Yes, a tredecillion is a legitimate, formally defined number. It is a cardinal number equal to 1042 in the US short-scale system — the digit 1 followed by exactly 42 zeros. It is not slang or an informal estimate; the name follows the systematic Latin-prefix convention used for all standard "-illion" names. See also: Zeros in a nonillion.
The table below places tredecillion in its sequence context:
| Name | Zeros | Scientific Notation |
|---|---|---|
| Duodecillion | 39 | 1039 |
| Tredecillion | 42 | 1042 |
| Quattuordecillion | 45 | 1045 |
The long-scale alternative of 1078 (78 zeros) uses the same word because both systems derive their names from the same Latin roots — only the step size (one million vs one thousand per name) differs. In modern English, tredecillion reliably means 42 zeros and 1042.
How Many Zeros Are in 10 Tredecillion and 100 Tredecillion?
Multiplying a tredecillion by powers of ten simply adds zeros to the exponent: Learn more about zeros in a novemdecillion.
- 1 tredecillion = 1042 — 42 zeros
- 10 tredecillion = 1043 — 43 zeros
- 100 tredecillion = 1044 — 44 zeros
- 1,000 tredecillion = 1045 — 45 zeros (= one quattuordecillion)
The pattern holds for any "-illion": each factor of 10 adds one zero, and each factor of 1,000 advances you to the next named number in the sequence. This is why scientific notation is the standard tool for tracking how many zeros are in any large number without writing out dozens of digits.