sextillions

Sextillion is a name assigned to a very large number. In the short-scale system used in the United States and in most scientific contexts, a sextillion equals 1 followed by 21 zeros (1,000,000,000,000,000,000,000). In the long-scale system formerly used in parts of Europe, a sextillion equals 10^36 (1 followed by 36 zeros). The term derives from the Latin sextus for “sixth” and the -illion suffix.

In the short scale, sextillion sits after quintillion, with the sequence: million 10^6, billion 10^9, trillion 10^12, quadrillion 10^15, quintillion 10^18, sextillion 10^21. In the long scale, sextillion is 10^36, and the interval between named powers grows by six zeros at each step: million 10^6, milliard 10^9, billion 10^12, billiard 10^15, trillion 10^18, quadrillion 10^24, quintillion 10^30, sextillion 10^36.

Usage and scope: The short-scale system is standard in modern English-language mathematics, science, and everyday use in most countries. The long-scale system is largely historical in many places, though some old texts and certain languages retain its terminology. In practical terms, sextillions appear mainly in theoretical contexts or as illustrative examples of very large numbers; precise counts at that scale are rarely encountered.

Examples and context: The observable universe is estimated to contain roughly 10^22 to 10^24 stars, placing the count in the range of about 10 to 1000 sextillions in short-scale terms.