Number

77

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

Arithmetic Number Deficient Number Evil Number Palindrome Recamán's Sequence Repdigit Semiprime Squarefree Year

Historical context — 77 AD

Calendar year

AD 77 (LXXVII) was a common year starting on Wednesday of the Julian calendar.

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Historical context — 77 BC

Calendar year

Year 77 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: Friday
January 1, 77
Ended on: Friday
December 31, 77
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 70s
70–79
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,949
1949 years before 2026.

In other calendars

Hebrew: 3837 / 3838 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Fire zodiac:Ox
Sexagenary cycle position 14 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 620 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 69 / 70 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): -1 / -2 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 2
Digit sum: 14
Digit product: 49
Digital root: 5
Palindrome: Yes
Bit width: 7 bits
Recamán's sequence: a(37) = 77
Square (n²): 5,929
Cube (n³): 456,533
Divisor count: 4
σ(n) — sum of divisors: 96
φ(n) — Euler's totient: 60
Sum of prime factors: 18

Primality

Prime factorization: 7 × 11

Nearest primes: 73 (−4) · 79 (+2)

Divisors & multiples

All divisors (4)

1 · 7 · 11 · 77

Aliquot sum (sum of proper divisors): 19

Factor pairs (a × b = 77)

1 × 77

7 × 11

First multiples

77 · 154 (double) · 231 · 308 · 385 · 462 · 539 · 616 · 693 · 770

Sums & aliquot sequence

As consecutive integers: 38 + 39 8 + 9 + … + 14 2 + 3 + … + 12

Aliquot sequence: 77 → 19 → 1 → 0 — terminates at zero

Representations

In words: seventy-seven
Ordinal: 77th
Roman numeral: LXXVII
Binary: 1001101
Octal: 115
Hexadecimal: 0x4D
Base64: TQ==
One's complement: 178 (8-bit)

In other bases

ternary (3) 2212

quaternary (4) 1031

quinary (5) 302

senary (6) 205

septenary (7) 140

nonary (9) 85

undecimal (11) 70

duodecimal (12) 65

tridecimal (13) 5c

tetradecimal (14) 57

pentadecimal (15) 52

Historical numeral systems

Babylonian (base 60): 𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): οζʹ
Mayan (base 20): 𝋣·𝋱
Chinese: 七十七
Chinese (financial): 柒拾柒

In other modern scripts

Eastern Arabic ٧٧ Devanagari ७७ Bengali ৭৭ Tamil ௭௭ Thai ๗๗ Tibetan ༧༧ Khmer ៧៧ Lao ໗໗ Burmese ၇၇

Digit at this position in famous constants

π — Pi (π): Digit 77 = 2
e — Euler's number (e): Digit 77 = 5
φ — Golden ratio (φ): Digit 77 = 9
√2 — Pythagoras's (√2): Digit 77 = 1
ln 2 — Natural log of 2: Digit 77 = 6
γ — Euler-Mascheroni (γ): Digit 77 = 6

Also seen as

ASCII character

As an ASCII codepoint, 77 is M. Printable ASCII character M.

Hex color

#00004D

RGB(0, 0, 77)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.77.

Address: 0.0.0.77
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.77

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

US numbered highway

Matches numbered highway designation:

I-77 — Columbia, SC to Cleveland, OH.

Interstate 77 on Wikipedia ↗