This number is a prime.
The first full and correct proof of the Fundamental Theorem of Arithmetic was first published by Gauss in his classic work Disquisitiones Arithmeticae (1801). The theorem states that every natural number greater than 1 can be written as a product of primes in exactly one way (apart from rearrangement).
The minor planet Ceres was found in the year 1801. [Poo Sung]
Contemporary painter Michael Eastman employs numbers, letters, and a William Morris pattern as abstract elements in the oil on canvas painting 1801: 14 Prime Numbers.
The smallest prime consisting of all of the cube digits (i.e., 0, 1, and 8) at least once. [Gupta]
(1801^2+1801+1)/3 = 1081801. [Vrba]
"Pure mathematics is religion." - Friedrich von Hardenberg, circa 1801
The smallest multidigit prime which is the number of ways to write n^2 as the sum of n odd numbers, disregarding order. In this case, n = 7 is also a prime. [Post]
Johann Bode’s Uranographia of 1801 is a classic star atlas. [Ridpath]