93 (number)

In mathematics

• the twenty-eighth distinct semiprime and the ninth of the form.
• the first number in the third triplet of consecutive semiprimes, 93, 94, and 95.
• a Blum integer, since its two prime factors, 3 and 31 are both Gaussian primes.
• a repdigit in base 5, and 30.
• palindromic in bases 2, 5, and 30.
• a lucky number.
• a cake number.
• an idoneal number.

In other fields

• The atomic number of neptunium, an actinide.
• The code for international direct dial phone calls to Afghanistan.
• One of two ISBN Group Identifiers for books published in India.
• The number of the French department Seine-Saint-Denis, and as such used by many French gangsta rappers and those emulating their speech.