67
67 is the nineteenth prime, and the atomic number of holmium — which has the strongest magnetic properties of any naturally occurring element and cuts kidney stones in surgical lasers.
- Odd
- Prime
Where 67 fits
Why 67 is special
67's primality (the 19th prime) is its main mathematical distinction, with no widely documented cultural association of its own.
67 connects to:
- 66 — is adjacent to
Same number, different meanings
How 67 is understood across different contexts — never implying one meaning because of another.
- Mathematics
67's primality (the 19th prime) is its main mathematical distinction, with no widely documented cultural association of its own.
- Technology & computing
DHCP hands a machine its IP address, gateway and DNS servers when it joins a network, using port 67 on the server and 68 on the client. It is the reason connecting to Wi-Fi requires no configuration, and the reason a network with a broken DHCP server appears to be down entirely.
- Science
67 is the atomic number of holmium, which has the strongest magnetic properties of any naturally occurring element. Holmium lasers are used in surgery, particularly for breaking up kidney stones.
67 is part of
Factors & digit properties
- Divisors (2)
- 1, 67
- Prime factorisation
- 67
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 67
- Scientific notation
- 6.700 × 10^1
Roman numerals
L X V I I
Binary
1 0 0 0 0 1 1
1 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 67
Octal
1 0 3
1 × 64 + 0 × 8 + 3 × 1 = 67
Hexadecimal
4 3
4 × 16 + 3 × 1 = 67
Read as powers of two: 64 + 2 + 1 = 67.
In historical numeral systems
Egyptian
6 hobbles, 7 strokes
6 × 10 + 7 × 1 = 67. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 vertical wedge (sixties place), 7 vertical wedges (units place)
1 × 60 + 7 = 67. Places are separated by a space on the tablet, with the higher place written first.
Greek (Ionic)
xi, then zeta, marked as a numeral
xi-zeta + keraia
xi + zeta written in descending order and added — the letters carry their values wherever they stand, so this is addition, not place value.
Hebrew numerals
samekh, then zayin
samekh-zayin
samekh (60) + zayin (7) = 67, written in descending order.
Chinese numerals
liù shí qī
liù shí qī
六 before 十 multiplies it: 6 tens. 七 after it adds 7. The written form mirrors the arithmetic — "liù shí qī". The financial (anti-fraud) form is 陸拾柒.
Maya
3 dots (upper, twenties place) over 1 bar + 2 dots (lower, units place)
3 × 20 + 7 = 67. 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
- Lucky number (mathematical sieve)
Related numbers & connections
67 and 66 are consecutive integers.
View 66 →Nearby in a sequence
- is adjacent to66
why?
Strength 0.50, confidence "high".
Technology & computing
DHCP hands a machine its IP address, gateway and DNS servers when it joins a network, using port 67 on the server and 68 on the client. It is the reason connecting to Wi-Fi requires no configuration, and the reason a network with a broken DHCP server appears to be down entirely.
DocumentedTechnology & computing
Science
67 is the atomic number of holmium, which has the strongest magnetic properties of any naturally occurring element. Holmium lasers are used in surgery, particularly for breaking up kidney stones.
DocumentedScience
Mathematics
67 is prime — the 19th prime number.
DocumentedMathematics
Common questions
Why does joining a Wi-Fi network need no configuration?
DHCP. When a device joins a network it broadcasts a request on port 67, and the server replies with an IP address, a gateway and DNS servers — everything that used to be typed in by hand. It is also why a network with a broken DHCP server looks completely dead rather than partly working: nothing gets far enough to fail visibly.
Is 67 a prime number?
Yes, 67 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 67?
The factors of 67 are 1, 67.
What is 67 in Roman numerals?
67 in Roman numerals is LXVII.
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