123 (number)

← 122 124 → 123
← 120 121 122 123 124 125 126 127 128 129 → List of numbers — Integers ← 100 110 120 130 140 150 160 170 180 190 →
Cardinal	one hundred [and] twenty-three
Ordinal	123rd (one hundred [and] twenty-third)
Numeral system	123
Factorization	$3 \cdot 41$
Divisors	1, 3, 41, 123
Roman numeral	CXXIII
Binary	11110112
Octal	1738
Duodecimal	A312
Hexadecimal	7B16

123 (one hundred [and] twenty-three) is the natural number following 122 and preceding 124.

In mathematics

• 123 is a Lucas number. It is the eleventh member of the Mian-Chowla sequence

In telephony

• The emergency telephone number in Colombia
• The telephone number of the speaking clock for the correct time in the United Kingdom
• The electricity emergency telephone number in Indonesia
• The medical emergency telephone number in Egypt
• The Notation for national and international telephone numbers Recommendation ITU-T Recommendation E.123 defines a standard way to write telephone numbers, e-mail addresses, and web addresses

In other fields

123 is also:

• Svea 123 is a small liquid-fuel naphtha, referred to as “white gas” or “Coleman fuel”
• The atomic number of the yet-to-be-discovered element unbitrium
• Japan Airlines Flight 123, world's deadliest single-aircraft accident in history

See also

• 1-2-3 (disambiguation)
• 123rd (disambiguation)
• List of highways numbered 123
• Section 123 Agreement of the U.S. Atomic Energy Act of 1954
• United Nations Security Council Resolution 123
• Raz, Dwa, Trzy, Polish music band
• Raz, dwa, trzy (newspaper), Polish sports weekly
• Sonnet 123 by William Shakespeare
• The Lotus 1-2-3 spreadsheet program