398
398 is a composite number, even, a calendar year.
Historical context — 398 AD
Calendar year
Year 398 (CCCXCVIII) was a common year starting on Friday of the Julian calendar.
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Historical context — 398 BC
Calendar year
Year 398 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
-
53
Long year: contains 53 ISO weeks.
- Started on
-
Thursday
January 1, 398
- Ended on
-
Thursday
December 31, 398
- Friday the 13ths
-
3
3 Friday the 13ths this year.
- Decade
-
390s
390–399
- Century
-
4th century
301–400
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,628
1628 years before 2026.
In other calendars
- Hebrew
-
4158 / 4159 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Dog
Sexagenary cycle position 35 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
941 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
390 / 391 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
320 / 319 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 × 199
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- three hundred ninety-eight
- Ordinal
- 398th
- Roman numeral
- CCCXCVIII
- Binary
- 110001110
- Octal
- 616
- Hexadecimal
- 0x18E
- Base64
- AY4=
- One's complement
- 65,137 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- τϟηʹ
- Mayan (base 20)
- 𝋳·𝋲
- Chinese
- 三百九十八
- Chinese (financial)
- 參佰玖拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 398 = 6
- e — Euler's number (e)
- Digit 398 = 1
- φ — Golden ratio (φ)
- Digit 398 = 9
- √2 — Pythagoras's (√2)
- Digit 398 = 8
- ln 2 — Natural log of 2
- Digit 398 = 6
- γ — Euler-Mascheroni (γ)
- Digit 398 = 3
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 398, here are decompositions:
- 19 + 379 = 398
- 31 + 367 = 398
- 61 + 337 = 398
- 67 + 331 = 398
- 127 + 271 = 398
- 157 + 241 = 398
- 199 + 199 = 398
UTF-8 encoding: C6 8E (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.142.
- Address
- 0.0.1.142
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.1.142
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.