Octillion vs. Septillion — What's the Difference?

The cardinal number that is equal to 1027.

The cardinal number equal to 1024.

Chiefly British The cardinal number that is equal to 1048.

Chiefly British The cardinal number equal to 1042.

A thousand trillion trillion, a billion billion billion: 1 followed by 27 zeros, 10²⁷.

A trillion trillion: 1 followed by 24 zeros, 10²⁴.

A trillion quintillion: 1 followed by 48 zeros, 10⁴⁸.

A billion quintillion: 1 followed by 42 zeros, 10⁴².

According to the French method of numeration (which method is followed also in the United States) the number expressed by a unit with twenty-seven ciphers annexed. According to the English method, the number expressed by a unit with forty-eight ciphers annexed. See Numeration.

According to the French method of numeration (which is followed also in the United States), the number expressed by a unit with twenty-four ciphers annexed. According to the English method, the number expressed by a unit with forty-two ciphers annexed. See Numeration.