Number

49

49 is a composite number, odd, a calendar year.

49 (forty-nine) is an odd 2-digit number. It is a composite number with 3 divisors, and factors as 7². It is a perfect square (7²). Written other ways, in Roman numerals it is XLIX and in binary, 110001.

Arithmetic Number Cube-Free Deficient Number Happy Number Odious Number Padovan Number Perfect Square Pernicious Number Powerful Number Recamán's Sequence Semiprime Year

Interestingness

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8 notable facts · grade A

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61

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Historical context — 49 AD

Calendar year

AD 49 (XLIX) was a common year starting on Wednesday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →

Notable events — 49 BC

Jan 10 Caesar crosses the Rubicon, beginning the civil war against Pompey.

Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0

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: Friday
January 1, 49
Ended on: Friday
December 31, 49
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 40s
40–49
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,977
1977 years before 2026.

In other calendars

Hebrew: 3809 / 3810 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Rooster
Sexagenary cycle position 46 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 592 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 41 / 42 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -29 / -30 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 2
Digit sum: 13
Digit product: 36
Digital root: 4
Palindrome: No
Bit width: 6 bits
Reversed: 94
Recamán's sequence: a(218) = 49
Square (n²): 2,401
Cube (n³): 117,649
Square root (√n): 7
Divisor count: 3
σ(n) — sum of divisors: 57
φ(n) — Euler's totient: 42
Sum of prime factors: 14

Primality

Prime factorization: 7 ²

Nearest primes: 47 (−2) · 53 (+4)

Divisors & multiples

All divisors (3)

1 · 7 · 49

Aliquot sum (sum of proper divisors): 8

Factor pairs (a × b = 49)

1 × 49

7 × 7

First multiples

49 · 98 (double) · 147 · 196 · 245 · 294 · 343 · 392 · 441 · 490

Sums & aliquot sequence

As a sum of two squares: 0² + 7²

As consecutive integers: 24 + 25 4 + 5 + … + 10

Aliquot sequence: 49 → 8 → 7 → 1 → 0 — terminates at zero

Representations

In words: forty-nine
Ordinal: 49th
Roman numeral: XLIX
Binary: 110001
Octal: 61
Hexadecimal: 0x31
Base64: MQ==
One's complement: 206 (8-bit)
Scientific notation: 4.9 × 10¹

In other bases

ternary (3) 1211

quaternary (4) 301

quinary (5) 144

senary (6) 121

septenary (7) 100

nonary (9) 54

undecimal (11) 45

duodecimal (12) 41

tridecimal (13) 3a

tetradecimal (14) 37

pentadecimal (15) 34

Palindromic in base 6

As an angle

49°

49° ≈ 0.855 rad

Compass bearing: NE (northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): μθʹ
Mayan (base 20): 𝋢·𝋩
Chinese: 四十九
Chinese (financial): 肆拾玖

In other modern scripts

Eastern Arabic ٤٩ Devanagari ४९ Bengali ৪৯ Tamil ௪௯ Thai ๔๙ Tibetan ༤༩ Khmer ៤៩ Lao ໔໙ Burmese ၄၉

Digit at this position in famous constants

π — Pi (π): Digit 49 = 5
e — Euler's number (e): Digit 49 = 9
φ — Golden ratio (φ): Digit 49 = 5
√2 — Pythagoras's (√2): Digit 49 = 6
ln 2 — Natural log of 2: Digit 49 = 0
γ — Euler-Mascheroni (γ): Digit 49 = 9

Also seen as

ASCII character

As an ASCII codepoint, 49 is 1. Printable ASCII character 1.

Hex color

#000031

RGB(0, 0, 49)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.49.

Address: 0.0.0.49
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.49

Unspecified address (0.0.0.0/8) — "this network" placeholder.

US numbered highway

Matches numbered highway designation:

I-49 — Lafayette, LA to Kansas City, MO (segments).

Interstate 49 on Wikipedia ↗

Geographic coordinate

As a geographic coordinate in degrees, this matches:

49th parallel (latitude) — The land border between most of the contiguous United States and Canada.

World map (equirectangular projection) — Latitude 49° — 49th parallel

Musical pitch

Heard as a frequency, 49 Hz is closest to:

Concert pitch (A4 = 440 Hz): G1 (49 Hz, exact)
Scientific pitch (C4 = 256 Hz): G1 (47.9 Hz, +38¢)
Baroque pitch (A4 = 415 Hz): G♯1 (49 Hz, +1¢)

(very low — many laptop and phone speakers can't reproduce it)

As a MIDI note number, 49 is C♯3 (138.6 Hz at concert pitch).

Atomic number

On the periodic table, atomic number 49 is Indium (In) — period 5.

Indium on Wikipedia ↗