253
253 is a composite number, odd, a calendar year.
253 (two hundred fifty-three) is an odd 3-digit number. It is a composite number with 4 divisors, and factors as 11 × 23. It is the 22nd triangular number. Written other ways, in Roman numerals it is CCLIII and in binary, 11111101.
Interestingness
Historical context — 253 AD
Calendar year
Year 253 (CCLIII) was a common year starting on Saturday of the Julian calendar.
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Historical context — 253 BC
Calendar year
Year 253 BC was a year of the pre-Julian Roman calendar.
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Year facts
- Year type
-
Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
- Days in year
- 365
- ISO weeks
- 52
- Started on
-
Saturday
January 1, 253
- Ended on
-
Saturday
December 31, 253
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
250s
250–259
- Century
-
3rd century
201–300
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,773
1773 years before 2026.
In other calendars
- Hebrew
-
4013 / 4014 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Water zodiac:Rooster
Sexagenary cycle position 10 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
796 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
245 / 246 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
175 / 174 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 11 × 23
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√253 = [15; (1, 9, 1, 1, 1, 2, 1, 7, 4, 2, 2, 2, 4, 7, 1, 2, 1, 1, 1, 9, 1, 30)]
Period length 22 — the block in parentheses repeats forever.
Representations
- In words
- two hundred fifty-three
- Ordinal
- 253rd
- Roman numeral
- CCLIII
- Binary
- 11111101
- Octal
- 375
- Hexadecimal
- 0xFD
- Base64
- /Q==
- One's complement
- 2 (8-bit)
- Scientific notation
- 2.53 × 10²
- As a duration
- 253 s = 4 minutes, 13 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹 𒌋𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺
- Greek (Milesian)
- σνγʹ
- Mayan (base 20)
- 𝋬·𝋭
- Chinese
- 二百五十三
- Chinese (financial)
- 貳佰伍拾參
Digit at this position in famous constants
- π — Pi (π)
- Digit 253 = 5
- e — Euler's number (e)
- Digit 253 = 2
- φ — Golden ratio (φ)
- Digit 253 = 3
- √2 — Pythagoras's (√2)
- Digit 253 = 9
- ln 2 — Natural log of 2
- Digit 253 = 5
- γ — Euler-Mascheroni (γ)
- Digit 253 = 4
Also seen as
UTF-8 encoding: C3 BD (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.253.
- Address
- 0.0.0.253
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.253
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 253 is an active NANP area code (North American Numbering Plan).
- Primary area
- Tacoma
- Region
- Washington
- Country
- United States
Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.
Heard as a frequency, 253 Hz is closest to:
- Concert pitch (A4 = 440 Hz): B3 (246.9 Hz, +42¢)
- Scientific pitch (C4 = 256 Hz): C4 (256 Hz, -20¢)
- Baroque pitch (A4 = 415 Hz): C4 (246.8 Hz, +43¢)
Related reading
- Triangular numbers — 1, 3, 6, 10, 15 … the counting numbers stacked into triangles, and Gauss's famous shortcut for summing them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.