Number

75

75 is a composite number, odd, a calendar year.

Deficient Number Evil Number Keith Number Nonagonal Recamán's Sequence Self Number Year

Historical context — 75 AD

Calendar year

AD 75 (LXXV) was a common year starting on Sunday of the Julian calendar.

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Historical context — 75 BC

Calendar year

Year 75 BC was a year of the pre-Julian Roman 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: 52
Started on: Tuesday
January 1, 75
Ended on: Tuesday
December 31, 75
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 70s
70–79
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,951
1951 years before 2026.

In other calendars

Hebrew: 3835 / 3836 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Wood zodiac:Pig
Sexagenary cycle position 12 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 618 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 67 / 68 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -3 / -4 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 2
Digit sum: 12
Digit product: 35
Digital root: 3
Palindrome: No
Bit width: 7 bits
Reversed: 57
Recamán's sequence: a(77) = 75
Square (n²): 5,625
Cube (n³): 421,875
Divisor count: 6
σ(n) — sum of divisors: 124
φ(n) — Euler's totient: 40
Sum of prime factors: 13

Primality

Prime factorization: 3 × 5 ²

Nearest primes: 73 (−2) · 79 (+4)

Divisors & multiples

All divisors (6)

1 · 3 · 5 · 15 · 25 · 75

Aliquot sum (sum of proper divisors): 49

Factor pairs (a × b = 75)

1 × 75

3 × 25

5 × 15

First multiples

75 · 150 (double) · 225 · 300 · 375 · 450 · 525 · 600 · 675 · 750

Sums & aliquot sequence

As consecutive integers: 37 + 38 24 + 25 + 26 13 + 14 + 15 + 16 + 17 10 + 11 + 12 + 13 + 14 + 15

Aliquot sequence: 75 → 49 → 8 → 7 → 1 → 0 — terminates at zero

Representations

In words: seventy-five
Ordinal: 75th
Roman numeral: LXXV
Binary: 1001011
Octal: 113
Hexadecimal: 0x4B
Base64: Sw==
One's complement: 180 (8-bit)

In other bases

ternary (3) 2210

quaternary (4) 1023

quinary (5) 300

senary (6) 203

septenary (7) 135

nonary (9) 83

undecimal (11) 69

duodecimal (12) 63

tridecimal (13) 5a

tetradecimal (14) 55

pentadecimal (15) 50

Historical numeral systems

Babylonian (base 60): 𒁹 𒌋𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): οεʹ
Mayan (base 20): 𝋣·𝋯
Chinese: 七十五
Chinese (financial): 柒拾伍

In other modern scripts

Eastern Arabic ٧٥ Devanagari ७५ Bengali ৭৫ Tamil ௭௫ Thai ๗๕ Tibetan ༧༥ Khmer ៧៥ Lao ໗໕ Burmese ၇၅

Digit at this position in famous constants

π — Pi (π): Digit 75 = 8
e — Euler's number (e): Digit 75 = 5
φ — Golden ratio (φ): Digit 75 = 1
√2 — Pythagoras's (√2): Digit 75 = 6
ln 2 — Natural log of 2: Digit 75 = 6
γ — Euler-Mascheroni (γ): Digit 75 = 7

Also seen as

ASCII character

As an ASCII codepoint, 75 is K. Printable ASCII character K.

Hex color

#00004B

RGB(0, 0, 75)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.75.

Address: 0.0.0.75
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.75

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

US numbered highway

Matches numbered highway designation:

I-75 — Hialeah, FL to Sault Ste. Marie, MI.

Interstate 75 on Wikipedia ↗