22
Twenty-two, written as 22, is the natural number that follows 21 and precedes 23. In common notations it is XXII in Roman numerals, 10110 in binary, and 0x16 in hexadecimal. It is an even composite number with prime factorization 2 × 11, and it has four positive divisors: 1, 2, 11, and 22.
In mathematics, 22 is a semiprime, the product of two primes. It is not a prime, nor
In science, 22 is the atomic number of titanium, a strong, light transition metal used in aerospace,
In culture and history, the 22nd Amendment to the U.S. Constitution, ratified in 1951, limits U.S. presidents