518

Number
$518$ (five hundred and eighteen) is:
 * $2 \times 7 \times 37$


 * The $49$th noncototient after $10, 26, 34, 50, \ldots, 386, 394, 404, 412, 436, 466, 470, 474, 482, 490$:
 * $\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 518$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function


 * The $40$th untouchable number after $2, 5, 52, 88, 96, 120, 124, \ldots, 324, 326, 336, 342, 372, 406, 408, 426, 430, 448, 472, 474, 498, 516$.


 * The $14$th number after $0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 89, 135, 175$ which is the sum of the increasing powers of its digits taken in order:
 * $5^1 + 1^2 + 8^3 = 518$


 * The $11$th even integer after $2, 4, 94, 96, 98, 400, 402, 404, 514, 516$ that cannot be expressed as the sum of $2$ prime numbers which are each one of a pair of twin primes.