65535 is the product of the first four Fermat primes:  65535 = (2 + 1)(4 + 1)(16 + 1)(256 + 1).
The number 65535 can be expressed as the result of multiplying together the first four prime numbers that are one more than a power of two: 65535 = (1+2) × (1+4) × (1+16) × (1+256).