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Number

1,388

1,388 is a composite number, even, a calendar year.

Arithmetic Number Deficient Number Evil Number Recamán's Sequence Year

Historical context — 1388 AD

Calendar year

Year 1388 (MCCCLXXXVIII) was a leap year starting on Wednesday of the Julian calendar.

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

Year facts

Year type
Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year
366
ISO weeks
52
Started on
Tuesday
January 1, 1388
Ended on
Wednesday
December 31, 1388
Friday the 13ths
1
One Friday the 13th this year.
Decade
1380s
1380–1389
Century
14th century
1301–1400
Millennium
2nd millennium
1001–2000
Years ago
638
638 years before 2026.

In other calendars

Hebrew
5148 / 5149 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
789 / 790 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Earth zodiac:Dragon
Sexagenary cycle position 5 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1931 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
766 / 767 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1380 / 1381 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1310 / 1309 Saka
Indian national calendar; year starts in March.

Properties

Parity
Even
Digit count
4
Digit sum
20
Digit product
192
Digital root
2
Palindrome
No
Bit width
11 bits
Reversed
8,831
Recamán's sequence
a(8,352) = 1,388
Square (n²)
1,926,544
Cube (n³)
2,674,043,072
Divisor count
6
σ(n) — sum of divisors
2,436
φ(n) — Euler's totient
692
Sum of prime factors
351

Primality

Prime factorization: 2 2 × 347

Nearest primes: 1,381 (−7) · 1,399 (+11)

Divisors & multiples

All divisors (6)
1 · 2 · 4 · 347 · 694 (half) · 1388
Aliquot sum (sum of proper divisors): 1,048
Factor pairs (a × b = 1,388)
1 × 1388
2 × 694
4 × 347
First multiples
1,388 · 2,776 (double) · 4,164 · 5,552 · 6,940 · 8,328 · 9,716 · 11,104 · 12,492 · 13,880

Sums & aliquot sequence

As consecutive integers: 170 + 171 + … + 177
Aliquot sequence: 1,388 1,048 932 706 356 274 140 196 203 37 1 0 — terminates at zero

Representations

In words
one thousand three hundred eighty-eight
Ordinal
1388th
Roman numeral
MCCCLXXXVIII
Binary
10101101100
Octal
2554
Hexadecimal
0x56C
Base64
BWw=
One's complement
64,147 (16-bit)
In other bases
ternary (3) 1220102
quaternary (4) 111230
quinary (5) 21023
senary (6) 10232
septenary (7) 4022
nonary (9) 1812
undecimal (11) 1052
duodecimal (12) 978
tridecimal (13) 82a
tetradecimal (14) 712
pentadecimal (15) 628

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵ατπηʹ
Mayan (base 20)
𝋣·𝋩·𝋨
Chinese
一千三百八十八
Chinese (financial)
壹仟參佰捌拾捌
In other modern scripts
Eastern Arabic ١٣٨٨ Devanagari १३८८ Bengali ১৩৮৮ Tamil ௧௩௮௮ Thai ๑๓๘๘ Tibetan ༡༣༨༨ Khmer ១៣៨៨ Lao ໑໓໘໘ Burmese ၁၃၈၈

Digit at this position in famous constants

π — Pi (π)
Digit 1,388 = 2
e — Euler's number (e)
Digit 1,388 = 9
φ — Golden ratio (φ)
Digit 1,388 = 9
√2 — Pythagoras's (√2)
Digit 1,388 = 2
ln 2 — Natural log of 2
Digit 1,388 = 3
γ — Euler-Mascheroni (γ)
Digit 1,388 = 0

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1388, here are decompositions:

  • 7 + 1381 = 1388
  • 61 + 1327 = 1388
  • 67 + 1321 = 1388
  • 97 + 1291 = 1388
  • 109 + 1279 = 1388
  • 139 + 1249 = 1388
  • 151 + 1237 = 1388
  • 157 + 1231 = 1388

Showing the first eight; more decompositions exist.

Unicode codepoint
լ
Armenian Small Letter Liwn
U+056C
Lowercase letter (Ll)

UTF-8 encoding: D5 AC (2 bytes).

Hex color
#00056C
RGB(0, 5, 108)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.5.108.

Address
0.0.5.108
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.5.108

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

Position in π

The digit sequence 1388 first appears in π at position 3,761 of the decimal expansion (the 3,761ordinal-suffix:st 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.