157
157 is a prime, odd, a calendar year.
157 (one hundred fifty-seven) is an odd 3-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is CLVII and in binary, 10011101.
Interestingness
Historical context — 157 AD
Calendar year
Year 157 (CLVII) was a common year starting on Friday of the Julian calendar.
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Historical context — 157 BC
Calendar year
Year 157 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
-
Saturday
January 1, 157
- Ended on
-
Saturday
December 31, 157
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
150s
150–159
- Century
-
2nd century
101–200
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,869
1869 years before 2026.
In other calendars
- Hebrew
-
3917 / 3918 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Fire zodiac:Rooster
Sexagenary cycle position 34 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
700 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
149 / 150 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
79 / 78 Saka
Indian national calendar; year starts in March.
Properties
Primality
157 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√157 = [12; (1, 1, 7, 1, 5, 2, 1, 1, 1, 1, 2, 5, 1, 7, 1, 1, 24)]
Period length 17 — the block in parentheses repeats forever.
Representations
- In words
- one hundred fifty-seven
- Ordinal
- 157th
- Roman numeral
- CLVII
- Binary
- 10011101
- Octal
- 235
- Hexadecimal
- 0x9D
- Base64
- nQ==
- One's complement
- 98 (8-bit)
- Scientific notation
- 1.57 × 10²
- As a duration
- 157 s = 2 minutes, 37 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ρνζʹ
- Mayan (base 20)
- 𝋧·𝋱
- Chinese
- 一百五十七
- Chinese (financial)
- 壹佰伍拾柒
Digit at this position in famous constants
- π — Pi (π)
- Digit 157 = 7
- e — Euler's number (e)
- Digit 157 = 0
- φ — Golden ratio (φ)
- Digit 157 = 4
- √2 — Pythagoras's (√2)
- Digit 157 = 1
- ln 2 — Natural log of 2
- Digit 157 = 1
- γ — Euler-Mascheroni (γ)
- Digit 157 = 6
Also seen as
UTF-8 encoding: C2 9D (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.157.
- Address
- 0.0.0.157
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.157
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 157 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯3 (155.6 Hz, +16¢)
- Scientific pitch (C4 = 256 Hz): E3 (161.3 Hz, -46¢ — about midway to D♯3)
- Baroque pitch (A4 = 415 Hz): E3 (155.4 Hz, +17¢)
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.