301

This number is a composite.

The number 301*2^184+1 is the smallest Proth prime with k = 301. [Patterson]

Any number (such as 301) with prime factors of the form x*(x+36), where x is a prime ending in 7, will end in ...01. E.g., 301 = (7*43), 901 = (17*53), 2701 = (37*73), 3901 = (47*83), etc.