1,551
1,551 is a composite number, odd, a calendar year.
Notable events — 1551 AD
- Apr 25 Pope Julius III re-opens the Council of Trent.
- Aug 14 The Ottomans capture Tripoli.
- Mar 14 Spain founds the National University of San Marcos in Lima.
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
-
Monday
January 1, 1551
- Ended on
-
Monday
December 31, 1551
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
1550s
1550–1559
- Century
-
16th century
1501–1600
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
475
475 years before 2026.
In other calendars
- Hebrew
-
5311 / 5312 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
957 / 958 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
-
2094 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
929 / 930 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1543 / 1544 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1473 / 1472 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 12
- Digit product
- 25
- Digital root
- 3
- Palindrome
- Yes
- Bit width
- 11 bits
- Recamán's sequence
- a(1,458) = 1,551
- Square (n²)
- 2,405,601
- Cube (n³)
- 3,731,087,151
- Divisor count
- 8
- σ(n) — sum of divisors
- 2,304
- φ(n) — Euler's totient
- 920
- Sum of prime factors
- 61
Primality
Prime factorization: 3 × 11 × 47
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand five hundred fifty-one
- Ordinal
- 1551st
- Roman numeral
- MDLI
- Binary
- 11000001111
- Octal
- 3017
- Hexadecimal
- 0x60F
- Base64
- Bg8=
- One's complement
- 63,984 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵αφναʹ
- Mayan (base 20)
- 𝋣·𝋱·𝋫
- Chinese
- 一千五百五十一
- Chinese (financial)
- 壹仟伍佰伍拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,551 = 6
- e — Euler's number (e)
- Digit 1,551 = 2
- φ — Golden ratio (φ)
- Digit 1,551 = 6
- √2 — Pythagoras's (√2)
- Digit 1,551 = 9
- ln 2 — Natural log of 2
- Digit 1,551 = 9
- γ — Euler-Mascheroni (γ)
- Digit 1,551 = 2
Also seen as
UTF-8 encoding: D8 8F (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.15.
- Address
- 0.0.6.15
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.15
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1551 first appears in π at position 6,432 of the decimal expansion (the 6,432ordinal-suffix:nd 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.