1,638
1,638 is a composite number, even, a calendar year.
Notable events — 1638 AD
- Feb 28 Scotland's National Covenant is signed against Charles I's religious policies.
- Apr 15 The Shimabara Rebellion is crushed in Japan.
- May 12 Dutch settlers establish New Sweden on the Delaware.
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, 1638
- Ended on
-
Friday
December 31, 1638
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 4
Sunday, April 4, 1638
- Decade
-
1630s
1630–1639
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
388
388 years before 2026.
In other calendars
- Hebrew
-
5398 / 5399 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1047 / 1048 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Earth zodiac:Tiger
Sexagenary cycle position 15 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2181 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1016 / 1017 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1630 / 1631 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1560 / 1559 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Even
- Digit count
- 4
- Digit sum
- 18
- Digit product
- 144
- Digital root
- 9
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 8,361
- Recamán's sequence
- a(676) = 1,638
- Square (n²)
- 2,683,044
- Cube (n³)
- 4,394,826,072
- Divisor count
- 24
- σ(n) — sum of divisors
- 4,368
- φ(n) — Euler's totient
- 432
- Sum of prime factors
- 28
Primality
Prime factorization: 2 × 3 2 × 7 × 13
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand six hundred thirty-eight
- Ordinal
- 1638th
- Roman numeral
- MDCXXXVIII
- Binary
- 11001100110
- Octal
- 3146
- Hexadecimal
- 0x666
- Base64
- BmY=
- One's complement
- 63,897 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αχληʹ
- Mayan (base 20)
- 𝋤·𝋡·𝋲
- Chinese
- 一千六百三十八
- Chinese (financial)
- 壹仟陸佰參拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,638 = 4
- e — Euler's number (e)
- Digit 1,638 = 1
- φ — Golden ratio (φ)
- Digit 1,638 = 9
- √2 — Pythagoras's (√2)
- Digit 1,638 = 9
- ln 2 — Natural log of 2
- Digit 1,638 = 3
- γ — Euler-Mascheroni (γ)
- Digit 1,638 = 3
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1638, here are decompositions:
- 11 + 1627 = 1638
- 17 + 1621 = 1638
- 19 + 1619 = 1638
- 29 + 1609 = 1638
- 31 + 1607 = 1638
- 37 + 1601 = 1638
- 41 + 1597 = 1638
- 59 + 1579 = 1638
Showing the first eight; more decompositions exist.
UTF-8 encoding: D9 A6 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.102.
- Address
- 0.0.6.102
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.102
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1638 first appears in π at position 32,307 of the decimal expansion (the 32,307ordinal-suffix:th digit after the integer 3).
Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.