0026

26 is the seventh discrete semiprime ( 2 × 13 {\displaystyle 2\times 13})and the fifth with 2 as the lowest non-unitary factor thus of the form (2.q), where q is a higher prime. 26 is the smallest even number n such that both n + 1 and n − 1 are composite. With an aliquot sum of 16, within an aliquot sequence of five composite numbers (26,16,15,9,4,3,1,0) to the Prime in the 3-aliquot tree. 26 is the only integer that is one greater than a square (52 + 1) and one less than a cube (33 − 1).