434

This number is a composite.

A palindrome that produces a Composed prime: 434 = 2 x 7 x 31 and 4² + 3⁷ + 4³¹ = 4611686018427390107 is prime. [De Geest]

434 is also the sum of the cubes of the digits of the emirp 347. [Trotter]

The smallest composite number n which satisfy the equation sigma(n+2) = sigma(n)+2, where sigma(n) is sum of divisors of n. [Gupta]