103

103 is an integer that follows 102 and precedes 104. It is most often encountered as a prime number in basic number theory and as a component of various numerical classifications.

In mathematics, 103 is prime; it is the 27th prime number. It is congruent to 3 modulo 4, so it cannot be expressed as the sum of two squares.

In notation, 103 is written in Roman numerals as CIII. In binary it is 1100111, in hexadecimal 0x67, and in octal 147.

In science, element 103 is lawrencium (Lr), a synthetic radioactive actinide. It is produced in minute quantities via particle accelerators and has no practical commercial applications beyond research.

In astronomy, Messier 103, abbreviated M103, is a small open cluster in the constellation Cassiopeia and is included in the Messier catalog; it was discovered by Pierre Méchain in the late 18th century.

In computing, the HTTP status code 103 refers to Early Hints, an informational response used to convey preliminary metadata before the final response to help browsers start loading resources earlier.

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