542
542 is a composite number, even, a calendar year.
542 (five hundred forty-two) is an even 3-digit number. It is a composite number with 4 divisors, and factors as 2 × 271. Written other ways, in Roman numerals it is DXLII and in binary, 1000011110.
Interestingness
Historical context — 542 AD
Calendar year
Year 542 (DXLII) was a common year starting on Wednesday of the Julian calendar.
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Historical context — 542 BC
Calendar year
The year 542 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
-
Monday
January 1, 542
- Ended on
-
Monday
December 31, 542
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
540s
540–549
- Century
-
6th century
501–600
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,484
1484 years before 2026.
In other calendars
- Hebrew
-
4302 / 4303 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Water zodiac:Dog
Sexagenary cycle position 59 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1085 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
534 / 535 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
464 / 463 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 × 271
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√542 = [23; (3, 1, 1, 3, 1, 1, 1, 22, 1, 1, 1, 3, 1, 1, 3, 46)]
Period length 16 — the block in parentheses repeats forever.
Representations
- In words
- five hundred forty-two
- Ordinal
- 542nd
- Roman numeral
- DXLII
- Binary
- 1000011110
- Octal
- 1036
- Hexadecimal
- 0x21E
- Base64
- Ah4=
- One's complement
- 64,993 (16-bit)
- Scientific notation
- 5.42 × 10²
- As a duration
- 542 s = 9 minutes, 2 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺
- Greek (Milesian)
- φμβʹ
- Mayan (base 20)
- 𝋡·𝋧·𝋢
- Chinese
- 五百四十二
- Chinese (financial)
- 伍佰肆拾貳
Digit at this position in famous constants
- π — Pi (π)
- Digit 542 = 1
- e — Euler's number (e)
- Digit 542 = 6
- φ — Golden ratio (φ)
- Digit 542 = 9
- √2 — Pythagoras's (√2)
- Digit 542 = 0
- ln 2 — Natural log of 2
- Digit 542 = 6
- γ — Euler-Mascheroni (γ)
- Digit 542 = 7
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 542, here are decompositions:
- 19 + 523 = 542
- 43 + 499 = 542
- 79 + 463 = 542
- 103 + 439 = 542
- 109 + 433 = 542
- 163 + 379 = 542
- 193 + 349 = 542
- 211 + 331 = 542
Showing the first eight; more decompositions exist.
UTF-8 encoding: C8 9E (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.30.
- Address
- 0.0.2.30
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.2.30
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 542 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C♯5 (554.4 Hz, -39¢)
- Scientific pitch (C4 = 256 Hz): C♯5 (542.4 Hz, -1¢)
- Baroque pitch (A4 = 415 Hz): D5 (554 Hz, -38¢)
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.