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Number

1,491

1,491 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Nonagonal Odious Number Pernicious Number Recamán's Sequence Self Number Sphenic Number Squarefree Year

Historical context — 1491 AD

Calendar year

Year 1491 (MCDXCI) was a common year starting on Saturday 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
Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year
365
ISO weeks
53
Long year: contains 53 ISO weeks.
Started on
Thursday
January 1, 1491
Ended on
Thursday
December 31, 1491
Friday the 13ths
3
3 Friday the 13ths this year.
Decade
1490s
1490–1499
Century
15th century
1401–1500
Millennium
2nd millennium
1001–2000
Years ago
535
535 years before 2026.

In other calendars

Hebrew
5251 / 5252 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
896 / 897 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Metal zodiac:Pig
Sexagenary cycle position 48 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
2034 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
869 / 870 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1483 / 1484 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1413 / 1412 Saka
Indian national calendar; year starts in March.

Properties

Parity
Odd
Digit count
4
Digit sum
15
Digit product
36
Digital root
6
Palindrome
No
Bit width
11 bits
Reversed
1,941
Recamán's sequence
a(1,578) = 1,491
Square (n²)
2,223,081
Cube (n³)
3,314,613,771
Divisor count
8
σ(n) — sum of divisors
2,304
φ(n) — Euler's totient
840
Sum of prime factors
81

Primality

Prime factorization: 3 × 7 × 71

Nearest primes: 1,489 (−2) · 1,493 (+2)

Divisors & multiples

All divisors (8)
1 · 3 · 7 · 21 · 71 · 213 · 497 · 1491
Aliquot sum (sum of proper divisors): 813
Factor pairs (a × b = 1,491)
1 × 1491
3 × 497
7 × 213
21 × 71
First multiples
1,491 · 2,982 (double) · 4,473 · 5,964 · 7,455 · 8,946 · 10,437 · 11,928 · 13,419 · 14,910

Sums & aliquot sequence

As consecutive integers: 745 + 746 496 + 497 + 498 246 + 247 + 248 + 249 + 250 + 251 210 + 211 + … + 216
Aliquot sequence: 1,491 813 275 97 1 0 — terminates at zero

Representations

In words
one thousand four hundred ninety-one
Ordinal
1491st
Roman numeral
MCDXCI
Binary
10111010011
Octal
2723
Hexadecimal
0x5D3
Base64
BdM=
One's complement
64,044 (16-bit)
In other bases
ternary (3) 2001020
quaternary (4) 113103
quinary (5) 21431
senary (6) 10523
septenary (7) 4230
nonary (9) 2036
undecimal (11) 1136
duodecimal (12) a43
tridecimal (13) 8a9
tetradecimal (14) 787
pentadecimal (15) 696

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian)
͵αυϟαʹ
Mayan (base 20)
𝋣·𝋮·𝋫
Chinese
一千四百九十一
Chinese (financial)
壹仟肆佰玖拾壹
In other modern scripts
Eastern Arabic ١٤٩١ Devanagari १४९१ Bengali ১৪৯১ Tamil ௧௪௯௧ Thai ๑๔๙๑ Tibetan ༡༤༩༡ Khmer ១៤៩១ Lao ໑໔໙໑ Burmese ၁၄၉၁

Digit at this position in famous constants

π — Pi (π)
Digit 1,491 = 9
e — Euler's number (e)
Digit 1,491 = 0
φ — Golden ratio (φ)
Digit 1,491 = 8
√2 — Pythagoras's (√2)
Digit 1,491 = 4
ln 2 — Natural log of 2
Digit 1,491 = 1
γ — Euler-Mascheroni (γ)
Digit 1,491 = 4

Also seen as

Unicode codepoint
ד
Hebrew Letter Dalet
U+05D3
Other letter (Lo)

UTF-8 encoding: D7 93 (2 bytes).

Hex color
#0005D3
RGB(0, 5, 211)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.5.211.

Address
0.0.5.211
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.5.211

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

Position in π

The digit sequence 1491 first appears in π at position 13,189 of the decimal expansion (the 13,189ordinal-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.