- The cardinal number equal to 10<sup>15</sup>.
- The cardinal number equal to 10<sup>24</sup>.
- The cardinal numeral obtained from a quadrillion: used like <internalXref urlencoded="hundred">hundred</internalXref>.
- The fourth power of a million according to the system of numeration called English; but the fifth power of a thousand according to the French system, commonly used in the United States.
- According to the French notation, which is followed also upon the Continent and in the United States, a unit with fifteen ciphers annexed; according to the English notation, the number produced by involving a million to the fourth power, or the number represented by a unit with twenty-four ciphers annexed. See the Note under <xref urlencoded="numeration">numeration</xref>.
- A <xref>thousand</xref> <xref>trillion</xref>: 1 followed by fifteen zeros, 1015.
- A <xref>million</xref> <xref>trillion</xref>: 1 followed by twenty-four zeros, 1024.
- Any very large number, exceeding normal description.
- the number that is represented as a one followed by 15 zeros
- the number that is represented as a one followed by 24 zeros