1,521
1,521 is a composite number, odd, a calendar year.
Notable events — 1521 AD
- Jan 3 Pope Leo X excommunicates Martin Luther.
- Apr 17 Luther defends himself at the Diet of Worms; he is outlawed.
- Apr 27 Magellan is killed in the Philippines.
- Aug 13 Cortés captures Tenochtitlan, ending the Aztec Empire.
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
-
Saturday
January 1, 1521
- Ended on
-
Saturday
December 31, 1521
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
1520s
1520–1529
- Century
-
16th century
1501–1600
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
505
505 years before 2026.
In other calendars
- Hebrew
-
5281 / 5282 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
927 / 928 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Snake
Sexagenary cycle position 18 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2064 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
899 / 900 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1513 / 1514 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1443 / 1442 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 9
- Digit product
- 10
- Digital root
- 9
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 1,251
- Recamán's sequence
- a(1,518) = 1,521
- Square (n²)
- 2,313,441
- Cube (n³)
- 3,518,743,761
- Square root (√n)
- 39
- Divisor count
- 9
- σ(n) — sum of divisors
- 2,379
- φ(n) — Euler's totient
- 936
- Sum of prime factors
- 32
Primality
Prime factorization: 3 2 × 13 2
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand five hundred twenty-one
- Ordinal
- 1521st
- Roman numeral
- MDXXI
- Binary
- 10111110001
- Octal
- 2761
- Hexadecimal
- 0x5F1
- Base64
- BfE=
- One's complement
- 64,014 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵αφκαʹ
- Mayan (base 20)
- 𝋣·𝋰·𝋡
- Chinese
- 一千五百二十一
- Chinese (financial)
- 壹仟伍佰貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,521 = 6
- e — Euler's number (e)
- Digit 1,521 = 9
- φ — Golden ratio (φ)
- Digit 1,521 = 9
- √2 — Pythagoras's (√2)
- Digit 1,521 = 6
- ln 2 — Natural log of 2
- Digit 1,521 = 0
- γ — Euler-Mascheroni (γ)
- Digit 1,521 = 1
Also seen as
UTF-8 encoding: D7 B1 (2 bytes).
TCP/UDP port 1521 is the registered port for Oracle DB — Oracle Database listener.
As an unsigned 32-bit integer, this is the IPv4 address 0.0.5.241.
- Address
- 0.0.5.241
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.5.241
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1521 first appears in π at position 1,315 of the decimal expansion (the 1,315ordinal-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.