# 1961

This number is a composite.

The first known titanic prime was found by Alexander Hurwitz in 1961.

1961 was the most recent strobogrammatic year. Note that the sum of its prime factors is 90, which contains the necessary digits to form the next such year, i.e., 6009. [Honaker]

(1+9+6+1)*1961 + 1*9*6*1, (1!*9!*6!*1!)*1961 - 1, & (1*9*6*1)!*1961*prime(1961) + 1, are primes. Note that 1961 is the smallest number with such properties. [Firoozbakht]

The second smallest strobogrammatic tnaillirb, i.e., a brilliant number whose reversal is a different brilliant number. Note that it is a permutation of 1691, which is the smallest strobogrammatic tnaillirb. [Post]

The only strobogrammatic tnaillirb concatenated from two double-digit primes and also the only strobogrammatic tnaillirb with prime-digit prime factors, 1961 = 37*53. [Loungrides]