Burt Kaliski Jr. (@modulomathy) 3/3/12 5:08 PM #math trivia for #March3: #63 is not a #Mersenne prime but it’s divisible by two of them. Which ones? (Mersenne p = 2^q-1, p, q prime.) The day’s number, 63, has the form 2^6-1, but neither the exponent 6 nor the number 63 is prime. However, both prime … Continue reading →