Number

1,901

1,901 is a prime, odd, a calendar year.

1,901 (one thousand nine hundred one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MCMI and in binary, 11101101101.

Arithmetic Number Chen Prime Cube-Free Deficient Number Emirp Evil Number Flippable Prime Pythagorean Prime Recamán's Sequence Sexy Prime Sophie Germain Prime Squarefree Year

Interestingness

★ ★ ★ ★ ★

11 notable facts · grade A

1,889 1,890 1,891 1,892 1,893 1,894 1,895 1,896 1,897 1,898 1,899 1,900 1,901 1,902 1,903 1,904 1,905 1,906 1,907 1,908 1,909 1,910 1,911 1,912 1,913

less more

Notable events — 1901 AD

Jan 22 Queen Victoria dies after a 63-year reign; her son Edward VII succeeds her.
Jan 10 The Spindletop gusher in Texas ignites the modern petroleum age.
Sep 6 US President William McKinley is shot at the Pan-American Exposition; he dies eight days later.
Sep 14 Theodore Roosevelt is sworn in as US president.
Dec 10 The first Nobel Prizes are awarded in Stockholm.

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: Tuesday
January 1, 1901
Ended on: Tuesday
December 31, 1901
Friday the 13ths: 2
2 Friday the 13ths this year.
Easter Sunday: April 7
Sunday, April 7, 1901
Decade: 1900s
1900–1909
Century: 20th century
1901–2000
Millennium: 2nd millennium
1001–2000
Years ago: 125
125 years before 2026.

In other calendars

Hebrew: 5661 / 5662 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1318 / 1319 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Ox
Sexagenary cycle position 38 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2444 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1279 / 1280 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1893 / 1894 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1823 / 1822 Saka
Indian national calendar; year starts in March.
Japanese: Meiji 34
Reign-era counting from the start of each emperor's reign.

Properties

Parity: Odd
Digit count: 4
Digit sum: 11
Digit product: 0
Digital root: 2
Palindrome: No
Bit width: 11 bits
Reversed: 1,091
Flips to (rotate 180°): 1,061
Recamán's sequence: a(7,942) = 1,901
Square (n²): 3,613,801
Cube (n³): 6,869,835,701
Divisor count: 2
σ(n) — sum of divisors: 1,902
φ(n) — Euler's totient: 1,900

Primality

1,901 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 1901

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 1,901)

1 × 1901

First multiples

1,901 · 3,802 (double) · 5,703 · 7,604 · 9,505 · 11,406 · 13,307 · 15,208 · 17,109 · 19,010

Sums & aliquot sequence

As a sum of two squares: 26² + 35²

As consecutive integers: 950 + 951

Continued fraction of √n

√1,901 = [43; (1, 1, 1, 1, 86)]

Period length 5 — the block in parentheses repeats forever.

Representations

In words: one thousand nine hundred one
Ordinal: 1901st
Roman numeral: MCMI
Binary: 11101101101
Octal: 3555
Hexadecimal: 0x76D
Base64: B20=
One's complement: 63,634 (16-bit)
Scientific notation: 1.901 × 10³
As a duration: 1,901 s = 31 minutes, 41 seconds

In other bases

ternary (3) 2121102

quaternary (4) 131231

quinary (5) 30101

senary (6) 12445

septenary (7) 5354

nonary (9) 2542

undecimal (11) 1479

duodecimal (12) 1125

tridecimal (13) b33

tetradecimal (14) 99b

pentadecimal (15) 86b

As an angle

1,901° = 5 × 360° + 101°

101° ≈ 1.763 rad

Compass bearing: E (east)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓏺
Greek (Milesian): ͵αϡαʹ
Mayan (base 20): 𝋤·𝋯·𝋡
Chinese: 一千九百零一
Chinese (financial): 壹仟玖佰零壹

In other modern scripts

Eastern Arabic ١٩٠١ Devanagari १९०१ Bengali ১৯০১ Tamil ௧௯௦௧ Thai ๑๙๐๑ Tibetan ༡༩༠༡ Khmer ១៩០១ Lao ໑໙໐໑ Burmese ၁၉၀၁

Digit at this position in famous constants

π — Pi (π): Digit 1,901 = 3
e — Euler's number (e): Digit 1,901 = 5
φ — Golden ratio (φ): Digit 1,901 = 7
√2 — Pythagoras's (√2): Digit 1,901 = 7
ln 2 — Natural log of 2: Digit 1,901 = 7
γ — Euler-Mascheroni (γ): Digit 1,901 = 1

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 1,889 (gap of 12)
Next prime: 1,907 (gap of 6)

Pair status: sexy with 1907.

Unicode codepoint

Arabic Letter Seen With Two Dots Vertically Above

U+076D

Other letter (Lo)

UTF-8 encoding: DD AD (2 bytes).

Lookup U+076D on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00076D

RGB(0, 7, 109)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.109.

Address: 0.0.7.109
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.7.109

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

Musical pitch

Heard as a frequency, 1,901 Hz is closest to:

Concert pitch (A4 = 440 Hz): A♯6 (1864.7 Hz, +33¢)
Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, -29¢)
Baroque pitch (A4 = 415 Hz): B6 (1863.3 Hz, +35¢)

Position in π

The digit sequence 1901 first appears in π at position 23,404 of the decimal expansion (the 23,404ordinal-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.

Look up 1901 on Pi Search ↗