174

This number is a composite.

The number of twin prime pairs among the first thousand primes. [Russ]

174 = 7² + 5³ (using the first four primes). [Trotter]

Landon Noll and Laura Nickel proved that M₂₁₇₀₁ was prime in a CDC Cyber174.

(There are 2 curios for this number that have not yet been approved by an editor.)