36

36 is a natural number that comes after 35 and before 37. In base-10 notation it is written as 36. It is an even composite number and is the square of 6, making it a square number.

Prime factorization: 2^2 × 3^2. It has nine divisors: 1, 2, 3, 4, 6, 9, 12, 18, 36. It is a triangular number (the eighth triangular number: T8 = 8×9/2 = 36) and a square triangular number (besides 1). It is an abundant number since the sum of its proper divisors (55) exceeds 36. It is a Harshad number in base 10 because 36 is divisible by the sum of its digits (3+6 = 9). In various bases: binary 100100, octal 44, hexadecimal 24, and Roman numerals XXXVI.

In measurement, 36 inches equal one yard. In science, 36 is the atomic number of krypton, a noble gas. It appears in cultural references: in China, the 36 Stratagems is a classic work on warfare; in film, The 36th Chamber of Shaolin is a well-known martial arts movie; and in probability, two six-sided dice have 36 equally likely outcomes.

Geography and numbering: the 36th parallel north is a circle of latitude. The number 36 is also associated with various symbolic uses, often tied to the factor 9 (since digits sum to 9).