In science, number of atoms in (something), such as 'one human', 'the earth', 'the sun', 'the galaxy', 'the universe', among other varieties, is a popular search query. The following table lists some of these atomic counts. [1] The third column, Exp, shows the old-fashioned calculator shorthand symbol for large numbers, in which E is short for exponent, in the sense that, for instance, E9 is short for 10E9 which is short for $10^9 \,$ .

#	Name	Number written out	Exp	Number of atoms in

1	one	1		$H \,$
2	two	2		$H_2 \,$
3	three	3		$H_2 O \,$
$10^2 \,$	hundred	100	E2
$10^3 \,$	thousand	1,000	E3
$10^6 \,$	million	1,000,000	E6
$10^9 \,$	billion	1,000,000,000	E9	(ten) bacteria molecules
$10^{12} \,$	trillion	1,000,000,000,000	E12
$10^{15} \,$	quadrillion	1,000,000,000,000,000	E15	(ten) pre-aquatic worms
$10^{18} \,$	quintillion	1,000,000,000,000,000,000	E18
$10^{21} \,$	sextillion	1,000,000,000,000,000,000,000	E21	(one) small fish
$10^{24} \,$	septillion	1,000,000,000,000,000,000,000,000	E24	Avogadro's number
$10^{27} \,$	octillion	1,000,000,000,000,000,000,000,000,000	E27	(one) human molecule (person)
$10^{30} \,$	nonillion	1,000,000,000,000,000,000,000,000,000,000	E30
$10^{33} \,$	decillion	1,000,000,000,000,000,000,000,000,000,000,000	E33
$10^{36} \,$	undecillion	1,000,000,000,000,000,000,000,000,000,000,000,000	E36
$10^{39} \,$	duodecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000	E39
$10^{42} \,$	tredecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E42
$10^{45} \,$	quattuordecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E45
$10^{48} \,$	quindecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E48
$10^{51} \,$	sexdecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E51	(one) earth molecule (the earth)
$10^{54} \,$	septendecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E54
$10^{57} \,$	octodecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E57	(one) sun molecule (the sun)
$10^{60} \,$	novemdecillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000	E60
$10^{63} \,$	vigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000	E63
$10^{66} \,$	unvigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000	E66	the milky way galaxy
$10^{69} \,$	duovigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000	E69
$10^{72} \,$	tresvigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000	E72
$10^{75} \,$	quattuorvigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000	E75
$10^{78} \,$	quinquavigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000	E78
$10^{81} \,$	sesvigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000	E81	the observable universe
$10^{84} \,$	septemvigintillion	1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000	E84

Multiverse
At the high end of the hypothetical estimates and speculative theories is the idea that the observable universe is connected to other 'parallel universes', possibly via wormholes (or other contrivances), such that the total set of parallel universes make up what is called the 'multiverse', of which one estimate indicates that at most there could be the following number of parallel universes: [2]

$10^{10^{16}} \,$ = number of parallel universes

which multiplied by the number of estimated atoms in our observable universe, indicates that there could be the following number of atoms in the multiverse:

$10^{81} \cdot 10^{10^{16}} \,$

or, using round-off, about:

$10^{10^{18}} \,$ = number of atoms in the multiverse (hypothetical)

Human molecule
In the English textual context, one would say that one person or one human molecule is comprised of an octillion atoms, of twenty-six types of 'active' elements.

References
1. Thims, Libb. (2008). The Human Molecule (preview) (Google Books). Morrisville, NC: LuLu.
2. Zyga, Lisa. (2009). “Physicists Calculate the Number of Parallel Universes”, Physorg.com, Oct. 16.

External links
● Names of larger numbers – Wikipedia.
● Number of atoms in the human body – NumberOf.net.