Hecho matemático: 652 is the only known non-perfect number whose number of divisors and sum of smaller divisors are perfect.
Trivia: 652 is a boring number.
Fecha histórica: October 13th is the day in 1892 that Edward Emerson Barnard discovers D/1892 T1, the first comet discovered by photographic means, on the night of October 13–14.