A Happy Number :)

86 (number) Article Talk Read Edit View history Tools Appearance hide Text Small Standard Large Width Standard Wide Color (beta) Automatic Light Dark From Wikipedia, the free encyclopedia ← 85 86 87 → ← 80 81 82 83 84 85 86 87 88 89 → List of numbersIntegers ← 0 10 20 30 40 50 60 70 80 90 → Cardinal eighty-six Ordinal 86th (eighty-sixth) Factorization 2 × 43 Divisors 1, 2, 43, 86 Greek numeral ΠϚ´ Roman numeral LXXXVI, lxxxvi Binary 10101102 Ternary 100123 Senary 2226 Octal 1268 Duodecimal 7212 Hexadecimal 5616 86 (eighty-six) is the natural number following 85 and preceding 87. In mathematics 86 is: nontotient[1] and a noncototient.[2] the 25th distinct semiprime[3] and the 13th of the form (2.q). together with 85 and 87, forms the middle semiprime in the 2nd cluster of three consecutive semiprimes; the first comprising 33, 34, 35.[4] an Erdős–Woods number, since it is possible to find sequences of 86 consecutive integers such that each inner member shares a factor with either the first or the last member.[5] a happy number[6] and a self number in base 10.[7] with an aliquot sum of 46; itself a semiprime, within an aliquot sequence of seven members (86,46,26,16,15,9,4,3,1,0) in the Prime 3-aliquot tree. It appears in the Padovan sequence, preceded by the terms 37, 49, 65 (it is the sum of the first two of these).[8] It is conjectured that 86 is the largest n for which the decimal expansion of 2n contains no 0.[9] 86 = (8 × 6 = 48) + (4 × 8 = 32) + (3 × 2 = 6). That is, 86 is equal to the sum of the numbers formed in calculating its multiplicative persistence.