101 (number)

The number 101 (one hundred and one) is the natural number following 100 and preceding 102.

Mathematics:

• 101 is the 26th prime number.
• It is a palindromic prime and a centered square number.
• It is a prime number of the form 4n + 1.
• 101 is a permutable prime with 11.
• In base 10, any six-digit number abcdef when multiplied by 10101 produces the number abcdefabcdef.

Other Uses:

• In many academic settings, particularly in North America, "101" is often used to designate introductory courses on a subject. This signifies the most basic level of understanding in the given field. For example, "Economics 101" or "Psychology 101."
• The term "101" is sometimes informally used to mean "basic," "introductory," or "fundamentals." As in, "This is Computer Programming 101."
• Various software or product names incorporate "101" to suggest a beginner-friendly or introductory nature.

Cultural References:

• 101 Dalmatians is a famous animated Disney film and subsequent live-action adaptation. The title refers to the number of Dalmatian dogs featured in the story.