813

813 = 3 x 271.

813 are the first three digits of 813^e.

813 is 393 in base 15.

813 is a divisor of 99999 (A027893) and 9999999999 (A027895): 99999/813 = 123 and 9999999999/813 = 12300123.

813 is the concatenation of the sixth Fibonacci number and the sixth prime (A138821).

Source: What's Special About This Number?