Twentysix

Twentysix is the natural number that follows twenty-five and precedes twenty-seven. In standard English usage the number is written as twenty-six, with a hyphen; twentysix may appear as a stylized variant in branding or informal writing.

In mathematics, 26 is an even composite number. Its prime factorization is 2 × 13, which makes it a semiprime. In decimal notation it is XXVI in Roman numerals, and its digits are 2 and 6. It is not a prime, nor a perfect square, and it has several small divisors: 1, 2, 13, and 26.

In science, 26 is the atomic number of iron, whose symbol is Fe. Iron is a common element in the Earth and a central material in metallurgy, biology (as a key component of hemoglobin), and industry.

Culturally, 26 holds significance in relation to the English alphabet, which comprises 26 letters and is often described as the “26-letter alphabet.” The number also appears in various historical and legal contexts; for example, the United States Constitution’s 26th Amendment, ratified in 1971, lowered the voting age to 18.

In other contexts, 26 is used in numeration systems, scheduling, and indexing where two-digit numbers commonly appear. As a widely recognized integer, it serves as a basic building block in counting, measurement, and coding schemes.