Number

245

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

Arithmetic Number Ascending Digits Deficient Number Evil Number Recamán's Sequence Year

Historical context — 245 AD

Calendar year

Year 245 (CCXLV) was a common year starting on Wednesday of the Julian calendar.

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Historical context — 245 BC

Calendar year

The year 245 BC was a year of the pre-Julian Roman calendar.

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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: Wednesday
January 1, 245
Ended on: Wednesday
December 31, 245
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 240s
240–249
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,781
1781 years before 2026.

In other calendars

Hebrew: 4005 / 4006 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Wood zodiac:Ox
Sexagenary cycle position 2 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 788 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 237 / 238 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 167 / 166 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 11
Digit product: 40
Digital root: 2
Palindrome: No
Bit width: 8 bits
Reversed: 542
Recamán's sequence: a(253) = 245
Square (n²): 60,025
Cube (n³): 14,706,125
Divisor count: 6
σ(n) — sum of divisors: 342
φ(n) — Euler's totient: 168
Sum of prime factors: 19

Primality

Prime factorization: 5 × 7 ²

Nearest primes: 241 (−4) · 251 (+6)

Divisors & multiples

All divisors (6)

1 · 5 · 7 · 35 · 49 · 245

Aliquot sum (sum of proper divisors): 97

Factor pairs (a × b = 245)

1 × 245

5 × 49

7 × 35

First multiples

245 · 490 (double) · 735 · 980 · 1,225 · 1,470 · 1,715 · 1,960 · 2,205 · 2,450

Sums & aliquot sequence

As a sum of two squares: 7² + 14²

As consecutive integers: 122 + 123 47 + 48 + 49 + 50 + 51 32 + 33 + … + 38 20 + 21 + … + 29

Aliquot sequence: 245 → 97 → 1 → 0 — terminates at zero

Representations

In words: two hundred forty-five
Ordinal: 245th
Roman numeral: CCXLV
Binary: 11110101
Octal: 365
Hexadecimal: 0xF5
Base64: 9Q==
One's complement: 10 (8-bit)

In other bases

ternary (3) 100002

quaternary (4) 3311

quinary (5) 1440

senary (6) 1045

septenary (7) 500

nonary (9) 302

undecimal (11) 203

duodecimal (12) 185

tridecimal (13) 15b

tetradecimal (14) 137

pentadecimal (15) 115

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σμεʹ
Mayan (base 20): 𝋬·𝋥
Chinese: 二百四十五
Chinese (financial): 貳佰肆拾伍

In other modern scripts

Eastern Arabic ٢٤٥ Devanagari २४५ Bengali ২৪৫ Tamil ௨௪௫ Thai ๒๔๕ Tibetan ༢༤༥ Khmer ២៤៥ Lao ໒໔໕ Burmese ၂၄၅

Digit at this position in famous constants

π — Pi (π): Digit 245 = 2
e — Euler's number (e): Digit 245 = 4
φ — Golden ratio (φ): Digit 245 = 6
√2 — Pythagoras's (√2): Digit 245 = 8
ln 2 — Natural log of 2: Digit 245 = 7
γ — Euler-Mascheroni (γ): Digit 245 = 5

Also seen as

Unicode codepoint

Latin Small Letter O With Tilde

U+00F5

Lowercase letter (Ll)

UTF-8 encoding: C3 B5 (2 bytes).

Lookup U+00F5 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0000F5

RGB(0, 0, 245)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.245.

Address: 0.0.0.245
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.245

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