Number

997

997 is a prime, odd, a calendar year.

Arithmetic Number Deficient Number Odious Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Year

Historical context — 997 AD

Calendar year

Year 997 (CMXCVII) was a common year starting on Friday of the Julian calendar.

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Historical context — 997 BC

Decade

The 990s BC is a decade that lasted from 999 BC to 990 BC.

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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: Sunday
January 1, 997
Ended on: Sunday
December 31, 997
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 990s
990–999
Century: 10th century
901–1000
Millennium: 1st millennium
1–1000
Years ago: 1,029
1029 years before 2026.

In other calendars

Hebrew: 4757 / 4758 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 386 / 387 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Fire zodiac:Rooster
Sexagenary cycle position 34 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1540 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 375 / 376 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 989 / 990 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 919 / 918 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 25
Digit product: 567
Digital root: 7
Palindrome: No
Bit width: 10 bits
Reversed: 799
Recamán's sequence: a(4,425) = 997
Square (n²): 994,009
Cube (n³): 991,026,973
Divisor count: 2
σ(n) — sum of divisors: 998
φ(n) — Euler's totient: 996

Primality

997 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 997

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 997)

1 × 997

First multiples

997 · 1,994 (double) · 2,991 · 3,988 · 4,985 · 5,982 · 6,979 · 7,976 · 8,973 · 9,970

Sums & aliquot sequence

As a sum of two squares: 6² + 31²

As consecutive integers: 498 + 499

Representations

In words: nine hundred ninety-seven
Ordinal: 997th
Roman numeral: CMXCVII
Binary: 1111100101
Octal: 1745
Hexadecimal: 0x3E5
Base64: A+U=
One's complement: 64,538 (16-bit)

In other bases

ternary (3) 1100221

quaternary (4) 33211

quinary (5) 12442

senary (6) 4341

septenary (7) 2623

nonary (9) 1327

undecimal (11) 827

duodecimal (12) 6b1

tridecimal (13) 5b9

tetradecimal (14) 513

pentadecimal (15) 467

Historical numeral systems

Babylonian (base 60): 𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ϡϟζʹ
Mayan (base 20): 𝋢·𝋩·𝋱
Chinese: 九百九十七
Chinese (financial): 玖佰玖拾柒

In other modern scripts

Eastern Arabic ٩٩٧ Devanagari ९९७ Bengali ৯৯৭ Tamil ௯௯௭ Thai ๙๙๗ Tibetan ༩༩༧ Khmer ៩៩៧ Lao ໙໙໗ Burmese ၉၉၇

Digit at this position in famous constants

π — Pi (π): Digit 997 = 0
e — Euler's number (e): Digit 997 = 5
φ — Golden ratio (φ): Digit 997 = 3
√2 — Pythagoras's (√2): Digit 997 = 8
ln 2 — Natural log of 2: Digit 997 = 3
γ — Euler-Mascheroni (γ): Digit 997 = 3

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 991 (gap of 6)
Next prime: 1,009 (gap of 12)

Pair status: sexy with 991.

Unicode codepoint

Coptic Small Letter Fei

U+03E5

Lowercase letter (Ll)

UTF-8 encoding: CF A5 (2 bytes).

Lookup U+03E5 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0003E5

RGB(0, 3, 229)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.229.

Address: 0.0.3.229
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.3.229

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