Zetta

From Wikipedia, the free encyclopedia

zetta- (symbol Z) is an SI prefix in the SI (system of units) denoting 10²¹ or 1 000 000 000 000 000 000 000.

Adopted in 1991, it comes from the Latin septem, meaning seven, because it is equal to 1000⁷.

A prefix of the same value, hepa-, was informally introduced a few years before the promulgation of zetta-. It was formed from the Greek ἑπτά, (hepta), also meaning seven. It never received official sanction and is now obsolete.

SI prefixes

1000n	10n	Prefix	Symbol	Short scale	Long scale	Decimal equivalent in SI writing style
10008	1024	yotta	Y	Septillion	Quadrillion	1 000 000 000 000 000 000 000 000
10007	1021	zetta	Z	Sextillion	Trilliard (thousand trillion)	1 000 000 000 000 000 000 000
10006	1018	exa	E	Quintillion	Trillion	1 000 000 000 000 000 000
10005	1015	peta	P	Quadrillion	Billiard (thousand billion)	1 000 000 000 000 000
10004	1012	tera	T	Trillion	Billion	1 000 000 000 000
10003	109	giga	G	Billion	Milliard (thousand million)	1 000 000 000
10002	106	mega	M	Million		1 000 000
10001	103	kilo	k	Thousand		1 000
10002/3	102	hecto	h	Hundred		100
10001/3	101	deca, deka	da	Ten		10
10000	100	(none)	(none)	One		1
1000−1/3	10−1	deci	d	Tenth		0.1
1000−2/3	10−2	centi	c	Hundredth		0.01
1000−1	10−3	milli	m	Thousandth		0.001
1000−2	10−6	micro	µ (u)	Millionth		0.000 001
1000−3	10−9	nano	n	Billionth	Milliardth	0.000 000 001
1000−4	10−12	pico	p	Trillionth	Billionth	0.000 000 000 001
1000−5	10−15	femto	f	Quadrillionth	Billiardth	0.000 000 000 000 001
1000−6	10−18	atto	a	Quintillionth	Trillionth	0.000 000 000 000 000 001
1000−7	10−21	zepto	z	Sextillionth	Trilliardth	0.000 000 000 000 000 000 001
1000−8	10−24	yocto	y	Septillionth	Quadrillionth	0.000 000 000 000 000 000 000 001

[edit] See also

• SI prefix
• Binary prefix

[edit] External link

• BIPM website