58
58 is the atomic number of cerium. The spark in a disposable lighter comes from ferrocerium, an alloy that sheds fragments hot enough to ignite in air when the wheel scrapes it.
- Even
- Composite
Where 58 fits
Why 58 is special
58's significance is an exact scientific identifier, not a mathematical property: cerium's fixed proton count. Despite belonging to the group popularly called "rare earths", cerium is actually the most abundant of them — more common in the Earth's crust than copper.
Same number, different meanings
How 58 is understood across different contexts — never implying one meaning because of another.
- Mathematics
58's significance is an exact scientific identifier, not a mathematical property: cerium's fixed proton count. Despite belonging to the group popularly called "rare earths", cerium is actually the most abundant of them — more common in the Earth's crust than copper.
- Science
The average distance from the Sun to Mercury is about 58 million kilometres (the Solar System). Its orbit is the most eccentric of the planets, so the distance swings between about 46 and 70 million kilometres.
- Technology & computing
The spark that lights a disposable lighter comes from element 58. Ferrocerium — an alloy of cerium and iron — is pyrophoric, which is why scraping it works at all: the wheel shaves off fragments small enough to ignite in air at a few hundred degrees, hot enough to light butane. The same alloy is sold as a fire steel for camping. Cerium is also the polishing compound used on optical glass and, in oxide form, part of the catalytic converter's oxygen-storage layer.
58 is part of
Factors & digit properties
- Divisors (4)
- 1, 2, 29, 58
- Prime factorisation
- 2 × 29
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 58
- Scientific notation
- 5.800 × 10^1
Roman numerals
L V I I I
Binary
1 1 1 0 1 0
1 × 32 + 1 × 16 + 1 × 8 + 0 × 4 + 1 × 2 + 0 × 1 = 58
Octal
7 2
7 × 8 + 2 × 1 = 58
Hexadecimal
3 a
3 × 16 + a × 1 = 58
Read as powers of two: 32 + 16 + 8 + 2 = 58.
In historical numeral systems
Egyptian
5 hobbles, 8 strokes
5 × 10 + 8 × 1 = 58. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
5 corner wedges + 8 vertical wedges
58 fits in a single sexagesimal place: 5 corner wedges + 8 vertical wedges.
Greek (Ionic)
nu, then eta, marked as a numeral
nu-eta + keraia
nu + eta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
nun, then het
nun-het
nun (50) + het (8) = 58, written in descending order.
Chinese numerals
wǔ shí bā
wǔ shí bā
五 before 十 multiplies it: 5 tens. 八 after it adds 8. The written form mirrors the arithmetic — "wǔ shí bā". The financial (anti-fraud) form is 伍拾捌.
Maya
2 dots (upper, twenties place) over 3 bars + 3 dots (lower, units place)
2 × 20 + 18 = 58. Places stack vertically with the smallest at the bottom, so the upper group is worth twenty times the lower.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
29 is a factor of 58 (29 × 2 = 58).
View 29 →58 is the atomic number of cerium.
58 appears in Numbers in space, the topic covering numbers that carry a documented astronomy fact.
Mathematically related
- has factor29
why?
Strength 0.50, confidence "high".
Scientific association
- has scientific association withCerium (chemical element)
why?
Strength 0.50, confidence "high".
Numbers Around Us
- appears inSpace and astronomy
why?
Strength 0.50, confidence "high".
Other connections
- is associated with862
why?
Strength 0.50, confidence "high".
Science
The average distance from the Sun to Mercury is about 58 million kilometres (the Solar System). Its orbit is the most eccentric of the planets, so the distance swings between about 46 and 70 million kilometres.
DocumentedScienceGeography: the Solar System58 is the atomic number of cerium, the most abundant of the rare-earth elements despite the name.
DocumentedScience
Technology & computing
The spark that lights a disposable lighter comes from element 58. Ferrocerium — an alloy of cerium and iron — is pyrophoric, which is why scraping it works at all: the wheel shaves off fragments small enough to ignite in air at a few hundred degrees, hot enough to light butane. The same alloy is sold as a fire steel for camping. Cerium is also the polishing compound used on optical glass and, in oxide form, part of the catalytic converter's oxygen-storage layer.
DocumentedTechnology & computing
Common questions
Is 58 a prime number?
No, 58 is not prime.
What are the factors of 58?
The factors of 58 are 1, 2, 29, 58.
What is 58 in Roman numerals?
58 in Roman numerals is LVIII.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026