900
900 is a composite number, even, a calendar year.
Notable events — 900 AD
- Undated The peak of the Maya Classic period collapse in Mesoamerica.
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
Historical context — 900 BC
Decade
The 900s BC is a decade that lasted from 909 BC to 900 BC.
Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →
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, 900
- Ended on
-
Friday
December 31, 900
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
900s
900–909
- Century
-
9th century
801–900
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,126
1126 years before 2026.
In other calendars
- Hebrew
-
4660 / 4661 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
286 / 288 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Monkey
Sexagenary cycle position 57 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1443 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
278 / 279 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
892 / 893 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
822 / 821 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Even
- Digit count
- 3
- Digit sum
- 9
- Digit product
- 0
- Digital root
- 9
- Palindrome
- No
- Bit width
- 10 bits
- Reversed
- 9
- Flips to (rotate 180°)
- 6
- Recamán's sequence
- a(407) = 900
- Square (n²)
- 810,000
- Cube (n³)
- 729,000,000
- Square root (√n)
- 30
- Divisor count
- 27
- σ(n) — sum of divisors
- 2,821
- φ(n) — Euler's totient
- 240
- Sum of prime factors
- 20
Primality
Prime factorization: 2 2 × 3 2 × 5 2
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- nine hundred
- Ordinal
- 900th
- Roman numeral
- CM
- Binary
- 1110000100
- Octal
- 1604
- Hexadecimal
- 0x384
- Base64
- A4Q=
- One's complement
- 64,635 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒁹𒁹𒁹𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢
- Greek (Milesian)
- ϡʹ
- Mayan (base 20)
- 𝋢·𝋥·𝋠
- Chinese
- 九百
- Chinese (financial)
- 玖佰
Digit at this position in famous constants
- π — Pi (π)
- Digit 900 = 0
- e — Euler's number (e)
- Digit 900 = 1
- φ — Golden ratio (φ)
- Digit 900 = 6
- √2 — Pythagoras's (√2)
- Digit 900 = 1
- ln 2 — Natural log of 2
- Digit 900 = 9
- γ — Euler-Mascheroni (γ)
- Digit 900 = 5
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 900, here are decompositions:
- 13 + 887 = 900
- 17 + 883 = 900
- 19 + 881 = 900
- 23 + 877 = 900
- 37 + 863 = 900
- 41 + 859 = 900
- 43 + 857 = 900
- 47 + 853 = 900
Showing the first eight; more decompositions exist.
UTF-8 encoding: CE 84 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.132.
- Address
- 0.0.3.132
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.3.132
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 900 is an active NANP area code (North American Numbering Plan).
- Primary area
- Premium-rate (caller pays)
- Region
- (special)
- Country
- North America
Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.